<PAGE>   1
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON NOVEMBER 20, 2000
                                                      REGISTRATION NO. 333-_____


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                   -----------
                                    FORM S-8

                             REGISTRATION STATEMENT
                                    UNDER THE
                             SECURITIES ACT OF 1933

                                     UBS AG
             (Exact Name of Registrant as Specified in Its Charter)

                                   SWITZERLAND
         (State or Other Jurisdiction of Incorporation or Organization)

                                   98-0186363
                     (I.R.S. Employer Identification Number)

                   BAHNHOFSTRASSE 45, ZURICH, SWITZERLAND, AND
                      AESCHENVORSTADT 1, BASEL, SWITZERLAND
                    (Address of Principal Executive Offices)

                            UBS AG OMNIBUS STOCK PLAN
                         UBS AG EQUITY INCENTIVE PROGRAM
                            (Full Title of the Plan)

                           ROBERT C. DINERSTEIN, ESQ.
                                     UBS AG
                                 299 PARK AVENUE
                            NEW YORK, NEW YORK 10171
                                 (212) 821-3000
            (Name, Address and Telephone Number of Agent for Service)

                                   COPIES TO:
                            MICHAEL M. WISEMAN, ESQ.
                            REBECCA J. SIMMONS, ESQ.
                               SULLIVAN & CROMWELL
                                125 BROAD STREET
                            NEW YORK, NEW YORK 10004
                                 (212) 558-4000

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
=======================================================================================================================
                                                                  PROPOSED MAXIMUM     PROPOSED MAXIMUM      AMOUNT OF
       TITLE OF EACH CLASS OF                                    OFFERING PRICE PER   AGGREGATE OFFERING   REGISTRATION
    SECURITIES TO BE REGISTERED     AMOUNT TO BE REGISTERED(1)         SHARE                PRICE               FEE
-----------------------------------------------------------------------------------------------------------------------
<S>                                <C>                           <C>                  <C>                  <C>
ORDINARY SHARES, PAR VALUE CHF 10        8,795,000                (2)               $1,200,077,750(2)       $316,821(2)
-----------------------------------------------------------------------------------------------------------------------
DEFERRED COMPENSATION OBLIGATIONS     $200,000,000               100%                 $200,000,000           $52,800
=======================================================================================================================
</TABLE>

     (1) IN ADDITION, PURSUANT TO RULE 416(C) UNDER THE SECURITIES ACT OF 1933,
         AS AMENDED, THIS REGISTRATION STATEMENT ALSO COVERS AN INDETERMINATE
         AMOUNT OF INTERESTS TO BE OFFERED OR SOLD PURSUANT TO THE EMPLOYEE
         BENEFIT PLAN(S) DESCRIBED HEREIN.

     (2) PURSUANT TO RULE 457(H)(1) AND 457(C) OF THE SECURITIES ACT OF 1933, AS
         AMENDED, THE PROPOSED MAXIMUM OFFERING PRICE AND THE AMOUNT OF THE
         REGISTRATION FEE HAVE BEEN COMPUTED ON THE BASIS OF A PRICE OF $136.45
         per UBS AG ORDINARY SHARE, THE AVERAGE OF THE HIGH AND LOW SALE PRICES
         PER UBS AG ORDINARY SHARE ON THE NEW YORK STOCK EXCHANGE COMPOSITE TAPE
         ON NOVEMBER 13, 2000.
<PAGE>   2
                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

                                EXPLANATORY NOTE



     As permitted by Rule 428 under the Securities Act of 1933, as amended
(the"Securities Act"), this registration statement omits the information
specified in Part I of Form S-8. The documents containing the information
specified in Part I will be delivered to the participants in the plan covered by
thi registration statement, as required by Rule 428(b) under the Securities
Act. Such documents are not being filed with the Securities and Exchange
Commission as part of this registration statement or as prospectuses or
prospectus supplements pursuant to Rule 424 under the Securities Act.




                                      -1-
<PAGE>   3
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.           INCORPORATION OF DOCUMENTS BY REFERENCE

         The following documents filed by UBS AG (the "Company") are hereby
incorporated by reference in this registration statement:

         The Company's Annual Report on Form 20-F for the year ended December
31, 1999, filed pursuant to the Securities Exchange Act of 1934 (the "Exchange
Act"), as amended or supplemented by the prospectus filed by the Company
pursuant to Rule 424(b)(1) on October 3, 2000;

         The Company's reports on Form 6-K filed on May 25, 2000, July 12, 2000,
July 17, 2000, July 26, 2000, October 2, 2000, October 11, 2000, October 24,
2000, October 27, 2000 and November 6, 2000 pursuant to the Exchange Act;

         The description of the Company's Ordinary Shares, par value CHF 10 per
share, contained in the Company's registration statement on Form 20-F filed with
the Commission on May 9, 2000, pursuant to the Exchange Act (Registration No.
00115026) including any amendments or reports filed for the purposes of updating
such description;

         All documents filed by the Company pursuant to Section 13(a) and 15(d)
of the Exchange Act after the date of this registration statement and prior to
the filing of a post-effective amendment to this registration statement which
indicates that all securities offered hereby have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference in this registration statement and to be a part hereof from the filing
date of such documents.

         Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of this registration statement to the extent that a statement
contained herein (or in any other subsequently filed document which also is
incorporated or deemed to be incorporated by reference herein) modifies or
supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
registration statement.

ITEM 4.           DESCRIPTION OF SECURITIES

UBS AG OMNIBUS STOCK PLAN.

                  Not applicable.

UBS AG EQUITY INCENTIVE PROGRAM.

DEFERRED COMPENSATION OBLIGATIONS.

         Under the UBS AG Equity Incentive Program (the "Program"), the Company
will provide eligible employees with the opportunity to defer a specified
percentage or dollar amount of their compensation or a portion of their annual
incentive award. This amount, along with any employer matching contribution
which may be provided for, will then be credited to an account which the Company
will establish on its books in the name of the eligible employee. Eligible
employees may elect to have amounts credited to their account under any of
several notional investment options, including, without limitation, notional UBS
ordinary shares, notional buy low or cash, or "BLOC" certificates or notional
UBS warrants.




                                      -2-
<PAGE>   4
         The obligation of the Company ultimately to pay such deferred amounts
in accordance with the Program (the "Deferred Compensation Obligations") will
be unsecured obligations of the Company and will rank pari passu with other
unsecured and unsubordinated indebtedness of the Company from time to time
outstanding. In addition, the rights of participants in the Program are subject
to the prior claims of creditors of the Company's subsidiaries. A description
of the Company's warrants and BLOC Certificates and any other deferred
investment indices will be included in the documents referred to in Part I of
this Registration Statement and delivered to participants in the Program.
Sample warrants and BLOC certificates, as well as sample terms and conditions
thereof, are filed as exhibits to this registration statement.


         The employee's election, in accordance with the terms of the Program,
will determine the amount of compensation to be deferred. At the time the
participant makes a deferral election, he or she will specify the date on which
payment of the balance of the account will be made or commenced.

         The Compensation Committee of the Office of the Chairman (the
"Committee") will from time to time identify the deferred investment indices
which may be used to measure the notional return (positive or negative) to be
credited or debited to the balance of a participant's account. The Committee
will also establish rules regarding each of the deferred investment indices. The
type of payment which participants may receive at the end of the deferral period
will depend on the rules applicable to the deferral investment index or indices
elected by that employee. Depending on the rules for a particular index,
obligations may be paid in the form of the Company's ordinary shares, in cash,
or in some combination thereof. A participant may also be allowed to make an
election to receive such payment in Company shares, in cash or in some
combination thereof.

         The rights, benefits and payments under the Program are not subject to
assignment, sale or other transfer nor are they liable or subject in any manner
to attachment, garnishment or execution; except that a participant will be
permitted to transfer and assign his or her rights under the Program to, but
only to, a trust, limited liability company or partnership of which all of the
beneficiaries, members or partners are either a) the transferring participant or
b) members of his or her immediate family. This type of transfer is subject,
however, to compliance with all applicable tax, securities and other laws and to
the responsible employer's determination (based on the advice of counsel) that
the assignment or transfer will not result in the occurrence of a taxable event.
Notwithstanding the above, a participant's right to the Deferred Compensation
Obligations may be transferred pursuant to a written designation of beneficiary
under the Program.

         Except in the case of the retirement, death or disability of the
participant, the Deferred Compensation Obligations are not subject to
redemption, in whole or in part, prior to the individual payment dates specified
by the participants, at the option of the Company or through operation of a
mandatory or optional sinking fund or analogous provision. However, the Company
reserves the right to amend or terminate the Program at any time, except that no
such amendment or termination shall reduce retroactively the right of a
participant to the balance of his or her deferred account as of the date of such
amendment or termination.

         The Deferred Compensation Obligations are not convertible into another
security of the Company. The Deferred Compensation Obligations will not have the
benefit of a negative pledge or any other affirmative or negative covenant on
the part of the Company. No trustee has been appointed having the authority to
take action with respect to the Deferred Compensation Obligations, and each
employee participant will be responsible for acting independently with respect
to, among other things, the giving of notices, responding to any requests for
consents, waivers or amendments pertaining to the Deferred Compensation
Obligations, enforcing covenants and taking action upon a default.

         The Program may be amended or terminated, including the terms and
conditions described above at any time, provided that any amendment of the
Program may not adversely affect the rights of any participant to receive
benefits under the Program in accordance with its terms in effect prior to such
amendment.


                                      -3-
<PAGE>   5
ITEM 5.           INTERESTS OF NAMED EXPERTS AND COUNSEL

                  Not applicable.

ITEM 6.           INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Neither the Company's articles of association nor Swiss statutory law
contain provisions regarding the indemnification of directors and officers.

         According to general principles of Swiss employment law, an employer
may, under certain circumstances, be required to indemnify an employee against
losses and expenses incurred by him in the execution of his duties under the
employment agreement, unless the losses and expenses arise from the employee's
gross negligence or willful misconduct.

         The Company maintains directors' and officers' insurance for its
directors and officers.

ITEM 7.           EXEMPTION FROM REGISTRATION CLAIMED

                  Not applicable.

ITEM 8.           EXHIBITS

<TABLE>
<CAPTION>
No.          Description
---          -----------

<S>          <C>
4.1          Articles of Association of UBS AG.

4.2          Organization Regulations of UBS AG.

4.3          UBS AG Equity Incentive Program.

4.4          Sample Global Warrant Certificate.

4.5          Sample Warrant Terms and Conditions.

4.6          Sample Global BLOC Certificate.

4.7          Sample BLOC Certificate Terms and Conditions

5.1          Opinion of Baer & Karrer, Swiss counsel to the Company.

23.1         Consent of Ernst & Young Ltd.

23.2         Consent of Baer & Karrer. (Included in Exhibit 5 hereto.)

24           Power of Attorney.
</TABLE>


ITEM 9.           UNDERTAKINGS

         The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:



                                      -4-
<PAGE>   6
         (i)      To include any prospectus required by Section 10(a)(3) of the
                  Securities Act;

         (ii)     To reflect in the prospectus any facts or events arising after
                  the effective date of this registration statement (or the most
                  recent post-effective amendment thereof) which, individually
                  or in aggregate, represent a fundamental change in the
                  information set forth in this registration statement.
                  Notwithstanding the foregoing, any increase or decrease in
                  volume of securities offered (if the total dollar value of
                  securities offered would not exceed that which was registered)
                  and any deviation from the low or high end of the estimated
                  maximum offering range may be reflected in the form of
                  prospectus filed with the Commission pursuant to Rule 424(b)
                  if, in the aggregate, the changes in volume and price
                  represent no more than 20 percent change in the maximum
                  aggregate offering price set forth in the "Calculation of
                  Registration Fee" table in the effective registration
                  statement;

         (iii)    To include any material information with respect to the plan
                  of distribution not previously disclosed in this registration
                  statement or any material change to such information in this
                  registration statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) of this Item 9 do
not apply if the information required to be included in the post-effective
amendment by those paragraphs is contained in periodic reports filed by the
Company pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in this registration statement.

(2) That, for the purpose of determining any liability under the Securities Act,
each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

(3) To remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold at the termination of the
offering.

(4) To file a post-effective amendment to the registration statement to include
any financial statements required by Item 8.A. of Form 20-F at the start of any
delayed offering or throughout a continuous offering. Financial statements and
information otherwise required by Section 10 (a) (3) of the Act need not be
furnished, provided, that the registrant includes in the prospectus, by means of
a post-effective amendment, financial statements required pursuant to this
paragraph (a) (4) and other information necessary to ensure that all other
information in the prospectus is at least as current as the date of those
financial statements. Notwithstanding the foregoing, with respect to
registration statements on Form F-3, a post-effective amendment need not be
filed to include financial statements and information required by Section 10(a)
(3) of the Act or Rule 3-19 of this chapter if such financial statements and
information are contained in periodic reports filed with or furnished to the
Commission by the registrant pursuant to Section 13, or Section 15 (d) of the
Securities Exchange Act of 1934, as amended, that are incorporated by reference
in the Form F-3.

(5) The undersigned Company hereby undertakes that, for purposes of determining
any liability under the Securities Act, each filing of the Company's annual
report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Exchange Act) that is incorporated by reference in this
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.



                                      -5-
<PAGE>   7
(6) Insofar as indemnification for liabilities arising under the Securities Act
of 1933, as amended, may be permitted to directors, officers and controlling
persons of the Company pursuant to the foregoing provisions, or otherwise, the
Company has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Company of expenses
incurred or paid by a director, officer or controlling person of the Company in
the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Company will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.






                                      -6-
<PAGE>   8
                                   SIGNATURES

         The Registrant. Pursuant to the requirements of the Securities Act of
1933, as amended, the Company certifies that it has reasonable grounds to
believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this registration statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Zurich, Switzerland, on
November 20, 2000.


                                    UBS AG



                                    By:  /s/ Luqman Arnold
                                        -----------------------------------
                                    Name:    Luqman Arnold
                                    Title:   Chief Financial Officer


                                    By:  /s/ Robert B. Mills
                                        -----------------------------------
                                    Name:    Robert B. Mills
                                    Title:   Managing Director

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this registration statement has been signed by the following persons in the
indicated capacities on November 20, 2000.

<TABLE>
<CAPTION>
Name                                         Title
----                                         -----

<S>                                          <C>
by:              *                           President and Group
      ---------------------------            Chief Executive Officer
Name: Marcel Ospel                           (Principal Executive Officer)

by:              *                           Chief Financial Officer
      ---------------------------            (Principal Financial Officer)
Name: Luqman Arnold

by:              *                           Group Controller
      ---------------------------            and Member of Group Managing Board
Name: Hugo Schaub                            (Principal Accounting Officer)

by:              *                           Chairman of the Board of Directors
      ---------------------------
Name: Alex Krauer


by:              *                           Vice Chairman of the Board of Directors
      ---------------------------
Name: Alberto Togni


by:              *                           Vice Chairman of the Board of Directors
      ---------------------------
Name: Markus Kundig
</TABLE>



                                      -7-
<PAGE>   9
<TABLE>
<S>                                          <C>
by:              *                           Member of the Board of Directors
      ---------------------------
Name: Peter Bockli


by:              *                           Member of the Board of Directors
      ---------------------------
Name: Eric Honegger


by:              *                           Member of the Board of Directors
      ---------------------------
Name: Rolf A. Meyer


by:              *                           Member of the Board of Directors
      ---------------------------
Name: Hans Peter Ming


by:                                          Member of the Board of Directors
      ---------------------------
Name: Andreas Reinhart
</TABLE>




*  By Power of Attorney


/s/ Luqman Arnold
------------------------------------
    Luqman Arnold





                                      -8-
<PAGE>   10
         Pursuant to the requirements of Section 6(a) of the Securities Act of
1933, as amended, the Authorized Representative has duly caused this
Registration Statement to be signed, solely in his capacity as the duly
authorized representative of UBS AG in the United States, in The City of New
York, State of New York, on the 20th day of November, 2000.




                                           By: /s/ Robert B. Mills
                                              ---------------------------
                                           Name:  Robert B. Mills
                                           Title: Managing Director





                                      -9-
<PAGE>   11
         The Plan. Pursuant to the requirements of the Securities Act of 1933,
as amended, the trustees (or other persons who administer the employee benefit
plan) have duly caused this registration statement to be signed on its behalf by
the undersigned, thereunto duly authorized, in The City of New York, State of
New York, on the 20th day of November, 2000.




                                         UBS AG EQUITY INCENTIVE PROGRAM



                                         By: /s/ Thomas F. Connolly
                                            -----------------------------
                                         Name: Thomas F. Connolly

                                         Title: Managing Directir, Global
                                                Compensation and Benefits






                                      -10-
<PAGE>   12
                                INDEX TO EXHIBITS

<TABLE>
<S>               <C>
4.1               Articles of Association of UBS AG.

4.2               Organization Regulations of UBS AG.

4.3               UBS AG Equity Incentive Program.

4.4               Sample Global Warrant Certificate.

4.5               Sample Warrant Terms and Conditions.

4.6               Sample Global BLOC Certificate.

4.7               Sample BLOC Certificate Terms and Conditions.

5.1               Opinion of Baer & Karrer, Swiss counsel to the Company.

23.1              Consent of Ernst & Young Ltd.

23.2              Consent of Baer & Karrer. (Included in Exhibit 5 hereto.)

24                Power of Attorney.
</TABLE>




                                      -11-
[{"type": "S-8", "sequence": "1", "filename": "y42938s-8.txt", "description": "UBS AG", "secsgml_size_bytes": 25482}]
{"company-data": {"conformed-name": "UBS AG", "cik": "0001114446", "assigned-sic": "6021", "irs-number": "000000000", "state-of-incorporation": "V8", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-50320", "film-number": "773861"}, "business-address": {"street1": "BAHNHOFSTRASSE 45", "city": "ZURICH SWITZERLAND", "state": "V8", "zip": "00000", "phone": "212-821-3000"}, "mail-address": {"street1": "BAHNHOFSTRASSE 45", "street2": "ZURICH", "city": "ZURICH SWITZERLAND", "state": "V8", "zip": "00000"}}
1
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON NOVEMBER 20, 2000
                                                      REGISTRATION NO. 333-_____

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                   -----------
                                    FORM S-8

                             REGISTRATION STATEMENT
                                    UNDER THE
                             SECURITIES ACT OF 1933

                                     UBS AG
             (Exact Name of Registrant as Specified in Its Charter)

                                   SWITZERLAND
         (State or Other Jurisdiction of Incorporation or Organization)

                                   98-0186363
                     (I.R.S. Employer Identification Number)

                   BAHNHOFSTRASSE 45, ZURICH, SWITZERLAND, AND
                      AESCHENVORSTADT 1, BASEL, SWITZERLAND
                    (Address of Principal Executive Offices)

                            UBS AG OMNIBUS STOCK PLAN
                         UBS AG EQUITY INCENTIVE PROGRAM
                            (Full Title of the Plan)

                           ROBERT C. DINERSTEIN, ESQ.
                                     UBS AG
                                 299 PARK AVENUE
                            NEW YORK, NEW YORK 10171
                                 (212) 821-3000
            (Name, Address and Telephone Number of Agent for Service)

                                   COPIES TO:
                            MICHAEL M. WISEMAN, ESQ.
                            REBECCA J. SIMMONS, ESQ.
                               SULLIVAN & CROMWELL
                                125 BROAD STREET
                            NEW YORK, NEW YORK 10004
                                 (212) 558-4000

                         CALCULATION OF REGISTRATION FEE
=======================================================================================================================
                                                                  PROPOSED MAXIMUM     PROPOSED MAXIMUM      AMOUNT OF
       TITLE OF EACH CLASS OF                                    OFFERING PRICE PER   AGGREGATE OFFERING   REGISTRATION
    SECURITIES TO BE REGISTERED     AMOUNT TO BE REGISTERED(1)         SHARE                PRICE               FEE
-----------------------------------------------------------------------------------------------------------------------
ORDINARY SHARES, PAR VALUE CHF 10        8,795,000                (2)               $1,200,077,750(2)       $316,821(2)
-----------------------------------------------------------------------------------------------------------------------
DEFERRED COMPENSATION OBLIGATIONS     $200,000,000               100%                 $200,000,000           $52,800
=======================================================================================================================
(1) IN ADDITION, PURSUANT TO RULE 416(C) UNDER THE SECURITIES ACT OF 1933,
         AS AMENDED, THIS REGISTRATION STATEMENT ALSO COVERS AN INDETERMINATE
         AMOUNT OF INTERESTS TO BE OFFERED OR SOLD PURSUANT TO THE EMPLOYEE
         BENEFIT PLAN(S) DESCRIBED HEREIN.

     (2) PURSUANT TO RULE 457(H)(1) AND 457(C) OF THE SECURITIES ACT OF 1933, AS
         AMENDED, THE PROPOSED MAXIMUM OFFERING PRICE AND THE AMOUNT OF THE
         REGISTRATION FEE HAVE BEEN COMPUTED ON THE BASIS OF A PRICE OF $136.45
         per UBS AG ORDINARY SHARE, THE AVERAGE OF THE HIGH AND LOW SALE PRICES
         PER UBS AG ORDINARY SHARE ON THE NEW YORK STOCK EXCHANGE COMPOSITE TAPE
         ON NOVEMBER 13, 2000.
2
                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

                                EXPLANATORY NOTE

     As permitted by Rule 428 under the Securities Act of 1933, as amended
(the"Securities Act"), this registration statement omits the information
specified in Part I of Form S-8. The documents containing the information
specified in Part I will be delivered to the participants in the plan covered by
thi registration statement, as required by Rule 428(b) under the Securities
Act. Such documents are not being filed with the Securities and Exchange
Commission as part of this registration statement or as prospectuses or
prospectus supplements pursuant to Rule 424 under the Securities Act.

                                      -1-
3
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.           INCORPORATION OF DOCUMENTS BY REFERENCE

         The following documents filed by UBS AG (the "Company") are hereby
incorporated by reference in this registration statement:

         The Company's Annual Report on Form 20-F for the year ended December
31, 1999, filed pursuant to the Securities Exchange Act of 1934 (the "Exchange
Act"), as amended or supplemented by the prospectus filed by the Company
pursuant to Rule 424(b)(1) on October 3, 2000;

         The Company's reports on Form 6-K filed on May 25, 2000, July 12, 2000,
July 17, 2000, July 26, 2000, October 2, 2000, October 11, 2000, October 24,
2000, October 27, 2000 and November 6, 2000 pursuant to the Exchange Act;

         The description of the Company's Ordinary Shares, par value CHF 10 per
share, contained in the Company's registration statement on Form 20-F filed with
the Commission on May 9, 2000, pursuant to the Exchange Act (Registration No.
00115026) including any amendments or reports filed for the purposes of updating
such description;

         All documents filed by the Company pursuant to Section 13(a) and 15(d)
of the Exchange Act after the date of this registration statement and prior to
the filing of a post-effective amendment to this registration statement which
indicates that all securities offered hereby have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference in this registration statement and to be a part hereof from the filing
date of such documents.

         Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of this registration statement to the extent that a statement
contained herein (or in any other subsequently filed document which also is
incorporated or deemed to be incorporated by reference herein) modifies or
supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
registration statement.

ITEM 4.           DESCRIPTION OF SECURITIES

UBS AG OMNIBUS STOCK PLAN.

                  Not applicable.

UBS AG EQUITY INCENTIVE PROGRAM.

DEFERRED COMPENSATION OBLIGATIONS.

         Under the UBS AG Equity Incentive Program (the "Program"), the Company
will provide eligible employees with the opportunity to defer a specified
percentage or dollar amount of their compensation or a portion of their annual
incentive award. This amount, along with any employer matching contribution
which may be provided for, will then be credited to an account which the Company
will establish on its books in the name of the eligible employee. Eligible
employees may elect to have amounts credited to their account under any of
several notional investment options, including, without limitation, notional UBS
ordinary shares, notional buy low or cash, or "BLOC" certificates or notional
UBS warrants.

                                      -2-
4
         The obligation of the Company ultimately to pay such deferred amounts
in accordance with the Program (the "Deferred Compensation Obligations") will
be unsecured obligations of the Company and will rank pari passu with other
unsecured and unsubordinated indebtedness of the Company from time to time
outstanding. In addition, the rights of participants in the Program are subject
to the prior claims of creditors of the Company's subsidiaries. A description
of the Company's warrants and BLOC Certificates and any other deferred
investment indices will be included in the documents referred to in Part I of
this Registration Statement and delivered to participants in the Program.
Sample warrants and BLOC certificates, as well as sample terms and conditions
thereof, are filed as exhibits to this registration statement.

         The employee's election, in accordance with the terms of the Program,
will determine the amount of compensation to be deferred. At the time the
participant makes a deferral election, he or she will specify the date on which
payment of the balance of the account will be made or commenced.

         The Compensation Committee of the Office of the Chairman (the
"Committee") will from time to time identify the deferred investment indices
which may be used to measure the notional return (positive or negative) to be
credited or debited to the balance of a participant's account. The Committee
will also establish rules regarding each of the deferred investment indices. The
type of payment which participants may receive at the end of the deferral period
will depend on the rules applicable to the deferral investment index or indices
elected by that employee. Depending on the rules for a particular index,
obligations may be paid in the form of the Company's ordinary shares, in cash,
or in some combination thereof. A participant may also be allowed to make an
election to receive such payment in Company shares, in cash or in some
combination thereof.

         The rights, benefits and payments under the Program are not subject to
assignment, sale or other transfer nor are they liable or subject in any manner
to attachment, garnishment or execution; except that a participant will be
permitted to transfer and assign his or her rights under the Program to, but
only to, a trust, limited liability company or partnership of which all of the
beneficiaries, members or partners are either a) the transferring participant or
b) members of his or her immediate family. This type of transfer is subject,
however, to compliance with all applicable tax, securities and other laws and to
the responsible employer's determination (based on the advice of counsel) that
the assignment or transfer will not result in the occurrence of a taxable event.
Notwithstanding the above, a participant's right to the Deferred Compensation
Obligations may be transferred pursuant to a written designation of beneficiary
under the Program.

         Except in the case of the retirement, death or disability of the
participant, the Deferred Compensation Obligations are not subject to
redemption, in whole or in part, prior to the individual payment dates specified
by the participants, at the option of the Company or through operation of a
mandatory or optional sinking fund or analogous provision. However, the Company
reserves the right to amend or terminate the Program at any time, except that no
such amendment or termination shall reduce retroactively the right of a
participant to the balance of his or her deferred account as of the date of such
amendment or termination.

         The Deferred Compensation Obligations are not convertible into another
security of the Company. The Deferred Compensation Obligations will not have the
benefit of a negative pledge or any other affirmative or negative covenant on
the part of the Company. No trustee has been appointed having the authority to
take action with respect to the Deferred Compensation Obligations, and each
employee participant will be responsible for acting independently with respect
to, among other things, the giving of notices, responding to any requests for
consents, waivers or amendments pertaining to the Deferred Compensation
Obligations, enforcing covenants and taking action upon a default.

         The Program may be amended or terminated, including the terms and
conditions described above at any time, provided that any amendment of the
Program may not adversely affect the rights of any participant to receive
benefits under the Program in accordance with its terms in effect prior to such
amendment.

                                      -3-
5
ITEM 5.           INTERESTS OF NAMED EXPERTS AND COUNSEL

                  Not applicable.

ITEM 6.           INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Neither the Company's articles of association nor Swiss statutory law
contain provisions regarding the indemnification of directors and officers.

         According to general principles of Swiss employment law, an employer
may, under certain circumstances, be required to indemnify an employee against
losses and expenses incurred by him in the execution of his duties under the
employment agreement, unless the losses and expenses arise from the employee's
gross negligence or willful misconduct.

         The Company maintains directors' and officers' insurance for its
directors and officers.

ITEM 7.           EXEMPTION FROM REGISTRATION CLAIMED

                  Not applicable.

ITEM 8.           EXHIBITS
No.          Description
---          -----------
4.1          Articles of Association of UBS AG.

4.2          Organization Regulations of UBS AG.

4.3          UBS AG Equity Incentive Program.

4.4          Sample Global Warrant Certificate.

4.5          Sample Warrant Terms and Conditions.

4.6          Sample Global BLOC Certificate.

4.7          Sample BLOC Certificate Terms and Conditions

5.1          Opinion of Baer & Karrer, Swiss counsel to the Company.

23.1         Consent of Ernst & Young Ltd.

23.2         Consent of Baer & Karrer. (Included in Exhibit 5 hereto.)

24           Power of Attorney.
ITEM 9.           UNDERTAKINGS

         The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:

                                      -4-
6
         (i)      To include any prospectus required by Section 10(a)(3) of the
                  Securities Act;

         (ii)     To reflect in the prospectus any facts or events arising after
                  the effective date of this registration statement (or the most
                  recent post-effective amendment thereof) which, individually
                  or in aggregate, represent a fundamental change in the
                  information set forth in this registration statement.
                  Notwithstanding the foregoing, any increase or decrease in
                  volume of securities offered (if the total dollar value of
                  securities offered would not exceed that which was registered)
                  and any deviation from the low or high end of the estimated
                  maximum offering range may be reflected in the form of
                  prospectus filed with the Commission pursuant to Rule 424(b)
                  if, in the aggregate, the changes in volume and price
                  represent no more than 20 percent change in the maximum
                  aggregate offering price set forth in the "Calculation of
                  Registration Fee" table in the effective registration
                  statement;

         (iii)    To include any material information with respect to the plan
                  of distribution not previously disclosed in this registration
                  statement or any material change to such information in this
                  registration statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) of this Item 9 do
not apply if the information required to be included in the post-effective
amendment by those paragraphs is contained in periodic reports filed by the
Company pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in this registration statement.

(2) That, for the purpose of determining any liability under the Securities Act,
each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

(3) To remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold at the termination of the
offering.

(4) To file a post-effective amendment to the registration statement to include
any financial statements required by Item 8.A. of Form 20-F at the start of any
delayed offering or throughout a continuous offering. Financial statements and
information otherwise required by Section 10 (a) (3) of the Act need not be
furnished, provided, that the registrant includes in the prospectus, by means of
a post-effective amendment, financial statements required pursuant to this
paragraph (a) (4) and other information necessary to ensure that all other
information in the prospectus is at least as current as the date of those
financial statements. Notwithstanding the foregoing, with respect to
registration statements on Form F-3, a post-effective amendment need not be
filed to include financial statements and information required by Section 10(a)
(3) of the Act or Rule 3-19 of this chapter if such financial statements and
information are contained in periodic reports filed with or furnished to the
Commission by the registrant pursuant to Section 13, or Section 15 (d) of the
Securities Exchange Act of 1934, as amended, that are incorporated by reference
in the Form F-3.

(5) The undersigned Company hereby undertakes that, for purposes of determining
any liability under the Securities Act, each filing of the Company's annual
report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Exchange Act) that is incorporated by reference in this
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

                                      -5-
7
(6) Insofar as indemnification for liabilities arising under the Securities Act
of 1933, as amended, may be permitted to directors, officers and controlling
persons of the Company pursuant to the foregoing provisions, or otherwise, the
Company has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Company of expenses
incurred or paid by a director, officer or controlling person of the Company in
the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Company will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.

                                      -6-
8
                                   SIGNATURES

         The Registrant. Pursuant to the requirements of the Securities Act of
1933, as amended, the Company certifies that it has reasonable grounds to
believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this registration statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Zurich, Switzerland, on
November 20, 2000.

                                    UBS AG

                                    By:  /s/ Luqman Arnold
                                        -----------------------------------
                                    Name:    Luqman Arnold
                                    Title:   Chief Financial Officer

                                    By:  /s/ Robert B. Mills
                                        -----------------------------------
                                    Name:    Robert B. Mills
                                    Title:   Managing Director

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this registration statement has been signed by the following persons in the
indicated capacities on November 20, 2000.
Name                                         Title
----                                         -----
by:              *                           President and Group
      ---------------------------            Chief Executive Officer
Name: Marcel Ospel                           (Principal Executive Officer)

by:              *                           Chief Financial Officer
      ---------------------------            (Principal Financial Officer)
Name: Luqman Arnold

by:              *                           Group Controller
      ---------------------------            and Member of Group Managing Board
Name: Hugo Schaub                            (Principal Accounting Officer)

by:              *                           Chairman of the Board of Directors
      ---------------------------
Name: Alex Krauer

by:              *                           Vice Chairman of the Board of Directors
      ---------------------------
Name: Alberto Togni

by:              *                           Vice Chairman of the Board of Directors
      ---------------------------
Name: Markus Kundig
-7-
9
by:              *                           Member of the Board of Directors
      ---------------------------
Name: Peter Bockli

by:              *                           Member of the Board of Directors
      ---------------------------
Name: Eric Honegger

by:              *                           Member of the Board of Directors
      ---------------------------
Name: Rolf A. Meyer

by:              *                           Member of the Board of Directors
      ---------------------------
Name: Hans Peter Ming

by:                                          Member of the Board of Directors
      ---------------------------
Name: Andreas Reinhart
*  By Power of Attorney

/s/ Luqman Arnold
------------------------------------
    Luqman Arnold

                                      -8-
10
         Pursuant to the requirements of Section 6(a) of the Securities Act of
1933, as amended, the Authorized Representative has duly caused this
Registration Statement to be signed, solely in his capacity as the duly
authorized representative of UBS AG in the United States, in The City of New
York, State of New York, on the 20th day of November, 2000.

                                           By: /s/ Robert B. Mills
                                              ---------------------------
                                           Name:  Robert B. Mills
                                           Title: Managing Director

                                      -9-
11
         The Plan. Pursuant to the requirements of the Securities Act of 1933,
as amended, the trustees (or other persons who administer the employee benefit
plan) have duly caused this registration statement to be signed on its behalf by
the undersigned, thereunto duly authorized, in The City of New York, State of
New York, on the 20th day of November, 2000.

                                         UBS AG EQUITY INCENTIVE PROGRAM

                                         By: /s/ Thomas F. Connolly
                                            -----------------------------
                                         Name: Thomas F. Connolly

                                         Title: Managing Directir, Global
                                                Compensation and Benefits

                                      -10-
12
                                INDEX TO EXHIBITS
4.1               Articles of Association of UBS AG.

4.2               Organization Regulations of UBS AG.

4.3               UBS AG Equity Incentive Program.

4.4               Sample Global Warrant Certificate.

4.5               Sample Warrant Terms and Conditions.

4.6               Sample Global BLOC Certificate.

4.7               Sample BLOC Certificate Terms and Conditions.

5.1               Opinion of Baer & Karrer, Swiss counsel to the Company.

23.1              Consent of Ernst & Young Ltd.

23.2              Consent of Baer & Karrer. (Included in Exhibit 5 hereto.)

24                Power of Attorney.
-11-