<PAGE>
 
  As filed with the Securities and Exchange Commission on December 15, 1998.

                              Registration No. 333-______

                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549
                                   __________

                                    FORM S-8
                             REGISTRATION STATEMENT
                                     Under
                           THE SECURITIES ACT OF 1933


                               ASECO CORPORATION
             (Exact name of registrant as specified in its charter)


                                   04-2816806
                      (I.R.S. employer identification no.)

                                    DELAWARE
         (State or other jurisdiction of incorporation or organization)

                500 DONALD LYNCH BOULEVARD, MARLBORO, MA  01752
              (Address of principal executive offices)  (Zip Code)


                       1993 EMPLOYEE STOCK PURCHASE PLAN
                           (Full title of the plans)


                         SEBASTIAN J. SICARI, PRESIDENT
                               ASECO CORPORATION
                           500 DONALD LYNCH BOULEVARD
                              MARLBORO, MA  01752
                    (Name and address of agent for service)

                                 (508) 481-8896
         (Telephone number, including area code, of agent for service)

                        CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION> 
================================================================================
                                          Proposed    Proposed               
                                           maximum     maximum       Amount
Title of securities         Amount        offering    aggregate        of     
to be                  to be registered   price per   offering    registration
registered                   (1)          share (2)   price (2)       fee
--------------------------------------------------------------------------------
<S>                    <C>                <C>         <C>         <C>
COMMON STOCK,                50,000       $2.0782     $103,910       $28.89
$.01 PAR VALUE
</TABLE>
================================================================================

(1)  Plus such additional number of shares as may be required pursuant to the
     plan in the event of a stock dividend, split-up of shares, recapitalization
     or other similar change in the Common Stock.

(2)  Estimated solely for the purpose of calculating the registration fee, in
     accordance with Rule 457(h)(1), on the basis of the average of the high and
     low prices of the Common Stock as reported on the Nasdaq National Market on
     December 10, 1998.
<PAGE>
 
                                EXPLANATORY NOTE

     This Registration Statement has been prepared in accordance with the
requirements of Form S-8, as amended, and relates to an aggregate of 50,000
shares of Common Stock, $.01 par value per share, of Aseco Corporation (the
"Company"), which represent the increase in the number of shares issuable under
the Company's 1993 Employee Stock Purchase Plan (the "Plan") approved by the
Board of Directors of the Company on June 18, 1998 and subsequently approved by
the stockholders of the Company on August 11, 1998.  The Company previously
filed with the Securities and Exchange Commission (the "Commission") on July 20,
1993 a Registration Statement on Form S-8 (File No. 33-66250), covering an
aggregate of 751,666 shares of the Company's Common Stock, including 100,000
shares then reserved for issuance under the Plan.
<PAGE>
 
                                    PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.   INCORPORATION BY REFERENCE.
          -------------------------- 

     The following documents are hereby incorporated by reference in this
Registration Statement:

     (a) The Company's Annual Report on Form 10-K for the year ended March 29,
1998, containing the Company's audited financial statements for the fiscal year
then ended;

     (b) The Company's Quarterly Report on Form 10-Q for the quarter ending June
28, 1998;

     (c) The Company's Quarterly Report on Form 10-Q for the quarter ending
September 27, 1998; and

     (d) The description of the Company's Common Stock contained in (i) the
Company's registration statement on Form 8-A filed with the Commission on
February 26, 1993, and (ii) the Company's registration statements on Form 8-A
and Form 8-A/A filed with the Commission on August 26, 1996 and August 28, 1996,
respectively.

     In addition, all documents filed by the Company after the initial filing
date of this Registration Statement pursuant to Sections 13(a), 13(c), 14 and
15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"),
and prior to the filing of a post-effective amendment which indicates that all
shares registered hereunder have been sold or which de-registers all shares then
remaining unsold, shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents.

ITEM 4.   DESCRIPTION OF SECURITIES
          -------------------------

     Not applicable.

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

     The legality of the shares of Common Stock offered hereby has been passed
upon for the Company by Choate, Hall & Stewart, 53 State Street, Exchange Place,
Boston, Massachusetts 02109.  Robert V. Jahrling, a partner of Choate, Hall &
Stewart, also serves as the Secretary of the Company.

                                      II-1
<PAGE>
 
ITEM 6.   INDEMNIFICATION OF OFFICERS AND DIRECTORS
          -----------------------------------------

     Section 145 of the General Corporation Law of the State of Delaware
provides that a corporation may indemnify a director, officer, employee or agent
against expenses (including attorneys' fees), judgments, fines and for amounts
paid in settlement in respect of or in successful defense of any action, suit or
proceeding if he or she acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of the corporation, and,
with respect to any criminal action or proceeding, had no reasonable cause to
believe his or her conduct was unlawful.

     Article Ninth of the Company's Third Restated Certificate of Incorporation
provides that no director of the Company shall be personally liable to the
Company or its stockholders for monetary damages for breach of fiduciary duty as
a director, except for liability (i) for any breach of the director's duty of
loyalty, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the Delaware General Corporation Law or (iv) for any transaction from which the
director derived an improper personal benefit.  Article Ninth further provides
that a director's personal liability shall be eliminated or limited in the
future to the fullest extent permitted from time to time by the Delaware General
Corporation Law.

     Article Tenth of the Company's Third Restated Certificate of Incorporation
provides that the Company shall, to the fullest extent permitted from time to
time under the Delaware General Corporation Law, indemnify each of its directors
and officers against all expenses (including attorneys' fees), judgments, fines
and amounts paid in settlement in respect of any action, suit or proceeding in
which such director or officer may be involved or with which he or she may be
threatened, while in office or thereafter, by reason of his or her actions or
omissions in connection with services to the Company, such indemnification to
include prompt payment of expenses in advance of the final disposition of any
such action, suit or proceeding.

ITEM 7.   EXEMPTION FROM REGISTRATION CLAIMED.
          ----------------------------------- 

     Not applicable.

ITEM 8.    EXHIBITS.
           -------- 

     5.1   Opinion of Choate, Hall & Stewart as to the legality of the shares
           being registered.

     23.1  Consent of Ernst & Young LLP.

     23.2  Consent of Choate, Hall & Stewart (included in Exhibit 5.1).

     24.1  Power of Attorney (included in page II-5).

     99.1* The Company's 1993 Employee Stock Purchase Plan (as amended and
           restated as of June 18, 1998).
--------------------------------------------------------------------------------
*Incorporated by reference to the Company's Quarterly Report on Form 10-Q for
the quarter ending June 28, 1998.

                                      II-2
<PAGE>
 
ITEM 9.   UNDERTAKINGS
          ------------

     (a)  The Company hereby undertakes:

          (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this Registration Statement to include any
material information with respect to the plan of distribution not previously
disclosed in the Registration Statement or any material change to such
information in the Registration Statement;

          (2) that, for the purpose of determining any liability under the
Securities Act of 1933, as amended (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; and

          (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.

     (b) The Company hereby undertakes that, for purpose of determining any
liability under the Securities Act, each filing of the Company's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the 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.

     (c) Insofar as indemnification for liabilities arising under the Securities
Act 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 Commission such indemnification is against
public policy as expressed in the Securities 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 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 Securities Act and will be governed by the final adjudication
of such issue.

                                      II-3
<PAGE>
 
                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, 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 Town of Marlboro, The Commonwealth of Massachusetts, on
December 15, 1998.

                              ASECO CORPORATION
                              (Registrant)



                              By:/s/ Sebastian J. Sicari
                                 --------------------------
                                 Sebastian J. Sicari
                                 President

                                      II-4
<PAGE>
 
                               POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below constitutes and appoints Sebastian J. Sicari and Robert V.
Jahrling, jointly and severally, his true and lawful attorneys-in-fact and
agents with full powers of substitution, for him or her and in his or her name,
place and stead, in any and all capacities, to sign any and all amendments
(including post-effective amendments) to this Registration Statement, and to
file the same, with all exhibits thereto, and all documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents, and each of them, full power and authority to do
and perform each and every act and thing requisite and necessary to be in and
about the premises, as fully to all intents and purposes as he or she might or
could do in person, hereby ratifying and confirming all that said attorneys-in-
fact and agents, or any of them, or their or his or her substitute or
substitutes, may lawfully do or cause to be done by virtue thereof.

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below on December 15, 1998 by the
following persons in the capacities indicated.

<TABLE>
<CAPTION>
NAME                       CAPACITY
----                       --------
<S>                        <C>
/s/ Sebastian J. Sicari    President, Chief Executive Officer and Director
-------------------------  (Principal Executive Officer)
Sebastian J. Sicari

 
/s/ Mary R. Barletta       Chief Financial Officer (Principal Financial
-------------------------  and Accounting Officer)
Mary R. Barletta           

 
/s/ Carl S. Archer, Jr.    Director
-------------------------
Carl S. Archer, Jr.

 
/s/ Sheldon Buckler        Director
-------------------------
Dr. Sheldon Buckler

 
                           Director
/s/ Sheldon Weinig
-------------------------
Dr. Sheldon Weinig

 
/s/ Gerald L. Wilson       Director
-------------------------
Dr. Gerald L. Wilson
 
</TABLE>

                                      II-5
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 14406}]
{"company-data": {"conformed-name": "ASECO CORP", "cik": "0000896645", "assigned-sic": "3825", "irs-number": "042816806", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-68907", "film-number": "98769503"}, "business-address": {"street1": "500 DONALD LYNCH BLVD", "city": "MARLBORO", "state": "MA", "zip": "01752", "phone": "5084818896"}, "mail-address": {"street1": "500 DONALD LYNCH BOULEVARD", "city": "MARLBORO", "state": "MA", "zip": "01752"}}
As filed with the Securities and Exchange Commission on December 15, 1998.

                              Registration No. 333-______

                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549
                                   __________

                                    FORM S-8
                             REGISTRATION STATEMENT
                                     Under
                           THE SECURITIES ACT OF 1933

                               ASECO CORPORATION
             (Exact name of registrant as specified in its charter)

                                   04-2816806
                      (I.R.S. employer identification no.)

                                    DELAWARE
         (State or other jurisdiction of incorporation or organization)

                500 DONALD LYNCH BOULEVARD, MARLBORO, MA  01752
              (Address of principal executive offices)  (Zip Code)

                       1993 EMPLOYEE STOCK PURCHASE PLAN
                           (Full title of the plans)

                         SEBASTIAN J. SICARI, PRESIDENT
                               ASECO CORPORATION
                           500 DONALD LYNCH BOULEVARD
                              MARLBORO, MA  01752
                    (Name and address of agent for service)

                                 (508) 481-8896
         (Telephone number, including area code, of agent for service)

                        CALCULATION OF REGISTRATION FEE
================================================================================
                                          Proposed    Proposed               
                                           maximum     maximum       Amount
Title of securities         Amount        offering    aggregate        of     
to be                  to be registered   price per   offering    registration
registered                   (1)          share (2)   price (2)       fee
--------------------------------------------------------------------------------
COMMON STOCK,                50,000       $2.0782     $103,910       $28.89
$.01 PAR VALUE
================================================================================

(1)  Plus such additional number of shares as may be required pursuant to the
     plan in the event of a stock dividend, split-up of shares, recapitalization
     or other similar change in the Common Stock.

(2)  Estimated solely for the purpose of calculating the registration fee, in
     accordance with Rule 457(h)(1), on the basis of the average of the high and
     low prices of the Common Stock as reported on the Nasdaq National Market on
     December 10, 1998.
EXPLANATORY NOTE

     This Registration Statement has been prepared in accordance with the
requirements of Form S-8, as amended, and relates to an aggregate of 50,000
shares of Common Stock, $.01 par value per share, of Aseco Corporation (the
"Company"), which represent the increase in the number of shares issuable under
the Company's 1993 Employee Stock Purchase Plan (the "Plan") approved by the
Board of Directors of the Company on June 18, 1998 and subsequently approved by
the stockholders of the Company on August 11, 1998.  The Company previously
filed with the Securities and Exchange Commission (the "Commission") on July 20,
1993 a Registration Statement on Form S-8 (File No. 33-66250), covering an
aggregate of 751,666 shares of the Company's Common Stock, including 100,000
shares then reserved for issuance under the Plan.
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION BY REFERENCE.
          -------------------------- 

     The following documents are hereby incorporated by reference in this
Registration Statement:

     (a) The Company's Annual Report on Form 10-K for the year ended March 29,
1998, containing the Company's audited financial statements for the fiscal year
then ended;

     (b) The Company's Quarterly Report on Form 10-Q for the quarter ending June
28, 1998;

     (c) The Company's Quarterly Report on Form 10-Q for the quarter ending
September 27, 1998; and

     (d) The description of the Company's Common Stock contained in (i) the
Company's registration statement on Form 8-A filed with the Commission on
February 26, 1993, and (ii) the Company's registration statements on Form 8-A
and Form 8-A/A filed with the Commission on August 26, 1996 and August 28, 1996,
respectively.

     In addition, all documents filed by the Company after the initial filing
date of this Registration Statement pursuant to Sections 13(a), 13(c), 14 and
15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"),
and prior to the filing of a post-effective amendment which indicates that all
shares registered hereunder have been sold or which de-registers all shares then
remaining unsold, shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents.

ITEM 4.   DESCRIPTION OF SECURITIES
          -------------------------

     Not applicable.

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

     The legality of the shares of Common Stock offered hereby has been passed
upon for the Company by Choate, Hall & Stewart, 53 State Street, Exchange Place,
Boston, Massachusetts 02109.  Robert V. Jahrling, a partner of Choate, Hall &
Stewart, also serves as the Secretary of the Company.

                                      II-1
ITEM 6.   INDEMNIFICATION OF OFFICERS AND DIRECTORS
          -----------------------------------------

     Section 145 of the General Corporation Law of the State of Delaware
provides that a corporation may indemnify a director, officer, employee or agent
against expenses (including attorneys' fees), judgments, fines and for amounts
paid in settlement in respect of or in successful defense of any action, suit or
proceeding if he or she acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of the corporation, and,
with respect to any criminal action or proceeding, had no reasonable cause to
believe his or her conduct was unlawful.

     Article Ninth of the Company's Third Restated Certificate of Incorporation
provides that no director of the Company shall be personally liable to the
Company or its stockholders for monetary damages for breach of fiduciary duty as
a director, except for liability (i) for any breach of the director's duty of
loyalty, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the Delaware General Corporation Law or (iv) for any transaction from which the
director derived an improper personal benefit.  Article Ninth further provides
that a director's personal liability shall be eliminated or limited in the
future to the fullest extent permitted from time to time by the Delaware General
Corporation Law.

     Article Tenth of the Company's Third Restated Certificate of Incorporation
provides that the Company shall, to the fullest extent permitted from time to
time under the Delaware General Corporation Law, indemnify each of its directors
and officers against all expenses (including attorneys' fees), judgments, fines
and amounts paid in settlement in respect of any action, suit or proceeding in
which such director or officer may be involved or with which he or she may be
threatened, while in office or thereafter, by reason of his or her actions or
omissions in connection with services to the Company, such indemnification to
include prompt payment of expenses in advance of the final disposition of any
such action, suit or proceeding.

ITEM 7.   EXEMPTION FROM REGISTRATION CLAIMED.
          ----------------------------------- 

     Not applicable.

ITEM 8.    EXHIBITS.
           -------- 

     5.1   Opinion of Choate, Hall & Stewart as to the legality of the shares
           being registered.

     23.1  Consent of Ernst & Young LLP.

     23.2  Consent of Choate, Hall & Stewart (included in Exhibit 5.1).

     24.1  Power of Attorney (included in page II-5).

     99.1* The Company's 1993 Employee Stock Purchase Plan (as amended and
           restated as of June 18, 1998).
--------------------------------------------------------------------------------
*Incorporated by reference to the Company's Quarterly Report on Form 10-Q for
the quarter ending June 28, 1998.

                                      II-2
ITEM 9.   UNDERTAKINGS
          ------------

     (a)  The Company hereby undertakes:

          (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this Registration Statement to include any
material information with respect to the plan of distribution not previously
disclosed in the Registration Statement or any material change to such
information in the Registration Statement;

          (2) that, for the purpose of determining any liability under the
Securities Act of 1933, as amended (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; and

          (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.

     (b) The Company hereby undertakes that, for purpose of determining any
liability under the Securities Act, each filing of the Company's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the 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.

     (c) Insofar as indemnification for liabilities arising under the Securities
Act 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 Commission such indemnification is against
public policy as expressed in the Securities 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 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 Securities Act and will be governed by the final adjudication
of such issue.

                                      II-3
SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, 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 Town of Marlboro, The Commonwealth of Massachusetts, on
December 15, 1998.

                              ASECO CORPORATION
                              (Registrant)

                              By:/s/ Sebastian J. Sicari
                                 --------------------------
                                 Sebastian J. Sicari
                                 President

                                      II-4
POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below constitutes and appoints Sebastian J. Sicari and Robert V.
Jahrling, jointly and severally, his true and lawful attorneys-in-fact and
agents with full powers of substitution, for him or her and in his or her name,
place and stead, in any and all capacities, to sign any and all amendments
(including post-effective amendments) to this Registration Statement, and to
file the same, with all exhibits thereto, and all documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents, and each of them, full power and authority to do
and perform each and every act and thing requisite and necessary to be in and
about the premises, as fully to all intents and purposes as he or she might or
could do in person, hereby ratifying and confirming all that said attorneys-in-
fact and agents, or any of them, or their or his or her substitute or
substitutes, may lawfully do or cause to be done by virtue thereof.

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below on December 15, 1998 by the
following persons in the capacities indicated.
NAME                       CAPACITY
----                       --------
/s/ Sebastian J. Sicari    President, Chief Executive Officer and Director
-------------------------  (Principal Executive Officer)
Sebastian J. Sicari

 
/s/ Mary R. Barletta       Chief Financial Officer (Principal Financial
-------------------------  and Accounting Officer)
Mary R. Barletta           

 
/s/ Carl S. Archer, Jr.    Director
-------------------------
Carl S. Archer, Jr.

 
/s/ Sheldon Buckler        Director
-------------------------
Dr. Sheldon Buckler

 
                           Director
/s/ Sheldon Weinig
-------------------------
Dr. Sheldon Weinig

 
/s/ Gerald L. Wilson       Director
-------------------------
Dr. Gerald L. Wilson
II-5