content: <PAGE>
  
  
                             UNITED STATES SEC USE ONLY
                               Washington, D.C. 20549
  
                                      FORM 144
  
                       NOTICE OF PROPOSED SALE OF SECURITIES
               PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
  
  --------------------------------------------------------------------------------
  1(a) NAME OF ISSUER (Please type or print) (b) IRS IDENT. NO.  (c) SEC FILE NO.
       L-3 Communications Holdings, Inc.         133937434           001-14141
  
  --------------------------------------------------------------------------------
  1(d) ADDRESS OF ISSUER  STREET  CITY   STATE   ZIP CODE    (e) TELEPHONE NO.
  600 Third Avenue, 34th Floor    New York, New York 10016       (212) 697-1111
  
  --------------------------------------------------------------------------------
  2(a) NAME OF PERSON FOR WHOSE  (b) SOCIAL SECURITY         (c) RELATIONSHIP
       ACCOUNT THE SECURITIES        NO. OR IRS IDENT. NO.       TO ISSUER
       ARE TO BE SOLD
  
       LaPenta, Robert V.            ###-##-####              President & CFO
  
  --------------------------------------------------------------------------------
  (d) ADDRESS        STREET              CITY                ZIP CODE
                        c/o L-3 Communications Corporation
                                 600 Third Avenue
                                New York, NY, 10016
  --------------------------------------------------------------------------------
  
  --------------------------------------------------------------------------------
  INSTRUCTION: The person filing this notice should contact the issuer to obtain
  the I.R.S. Identification Number and the SEC File Number.
  --------------------------------------------------------------------------------
  <TABLE>
  <CAPTION>
  
  3(a)            (b)                             SEC USE ONLY  (c)                   (d)                   (e)
                     Name and Address of Each     ------------     Number of Shares        Aggregate            Number of Shares
   Title of the      Broker Through Whom the                        or Other Units           Market              or Other Units
     Class of      Securities are to be Offered   Broker-Dealer       To Be Sold             Value                 Outstanding
    Securities     or Each Market Maker who is     File Number
    To Be Sold       Acquiring the Securities                     (See instr. 3(c))     (See instr. 3(d))       (See instr. 3(e))
  <S>             <C>                            <C>            <C>                   <C>                   <C>
  ------------------------------------------------------------------------------------------------------------------------------------
  Common Stock     Morgan Stanley                                       300,000            $17,742,000              106,920,648
                   1585 Broadway
                   New York, NY 10036
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  
  <CAPTION>
  
  (f)                      (g)
      Approximate               Name of Each
      Date of Sale               Securities
                                  Exchange
   (See instr. 3(f))
    (MO.  DAY  YR.)          (See instr. 3(g))
  <S>                      <C>
  ------------------------------------------------------------------------------------------------------------------------------------
       08/13/04                    NYSE
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  </TABLE>
  
  
  <PAGE>
  
                          TABLE I - SECURITIES TO BE SOLD
  
  Furnish the following information with respect to the acquisition of the
  securities to be sold and with respect to the payment of all or any part of the
  purchase price or other consideration therefor:
  
  <TABLE>
  <CAPTION>
                                                 Name of Person
                                                 from Whom Acquired
  Title of   Date You  Nature of                 (If gift, also give date   Amount of             Date of
  the Class  Acquired  Acquisition Transaction   donor acquired)            Securities Acquired   Payment     Nature of Payment
  <S>       <C>       <C>                       <C>                        <C>                   <C>         <C>
  ------------------------------------------------------------------------------------------------------------------------------------
  Common     4/1/96    Private Transaction       L-3 Communications           2,944,000(1)         4/1/96     Check
  Stock                                          Holdings, Inc.
  ------------------------------------------------------------------------------------------------------------------------------------
  </TABLE>
  
  INSTRUCTIONS: If the securities were purchased and full payment therefor was not
                made in cash at the time of purchase, explain in the table or in a
                note thereto the nature of the consideration given. If the
                consideration consisted of any note or other obligation, or if
                payment was made in installments describe the arrangement and
                state when the note or other obligation was discharged in full or
                the last installment paid.
  
  
                TABLE II - SECURITIES SOLD DURING THE PAST 3 MONTHS
  
  Furnish the following information as to all securities of the issuer sold during
  the past 3 months by the person for whose account the securities are to be sold.
  
  <TABLE>
  <CAPTION>
                                                                                 Amount of     Gross
  Name and Address of Seller         Title of Securities Sold    Date of Sale    Securities    Proceeds
  <S>                               <C>                         <C>             <C>           <C>
  -------------------------------------------------------------------------------------------------------
  
  
  
  
  -------------------------------------------------------------------------------------------------------
  </TABLE>
  
  REMARKS:
  
  In accordance with the procedures described in the Commission's interpretive
  letter to Goldman, Sachs & Co. dated December 20, 1999, this Form 144 is being
  filed in connection with the sale of 300,000 shares of the Common Stock of L-3
  Communications Holdings, Inc. to Morgan Stanley pursuant to a Variable Prepaid
  Forward Contract. The final pricing terms of the Variable Prepaid Forward
  Contract will be determined by the average sales price that Morgan Stanley will
  be able to obtain for an equivalent number of shares of L-3 Communications
  Holdings, Inc. Common Stock.
  
  (1) As adjusted for two-for-one stock split announced on April 23, 2002.
  
  
  INSTRUCTIONS:
  
  See the definition of "person" in paragraph (a) of Rule 144. Information is to
  be given not only as to the person for whose account the securities are to be
  sold but also as to sales by all persons whose sales are required by paragraph
  (e) of Rule 144 to be aggregated with sales for the account of the person filing
  this notice.
  
  ATTENTION:
  
  The person for whose account the securities to which this notice relates are to
  sold hereby represents by signing this notice that he does not know any material
  adverse information in regard to the current and prospective operations of the
  Issuer of the securities to be sold which have not been publicly disclosed.
  
  Date: 08/13/2004                     /s/ Robert V. LaPenta
        ------------------              ------------------------------------------
  
  
  The notice shall be signed by the person for whose account the securities are to
  be sold. At least one copy of the notice shall be manually signed. Any copies
  not manually signed shall bear typed or printed signatures.
  
  ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSION OF FACTS CONSTITUTE FEDERAL
  CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001).
metadata_documents: [{"type": "144", "sequence": "1", "filename": "file001.txt", "description": "FORM 144; NOTICE OF PROPOSED SALE OF SECURITIES", "secsgml_size_bytes": 8451}]
text: UNITED STATES SEC USE ONLY
                               Washington, D.C. 20549
  
                                      FORM 144
  
                       NOTICE OF PROPOSED SALE OF SECURITIES
               PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
  
  --------------------------------------------------------------------------------
  1(a) NAME OF ISSUER (Please type or print) (b) IRS IDENT. NO.  (c) SEC FILE NO.
       L-3 Communications Holdings, Inc.         133937434           001-14141
  
  --------------------------------------------------------------------------------
  1(d) ADDRESS OF ISSUER  STREET  CITY   STATE   ZIP CODE    (e) TELEPHONE NO.
  600 Third Avenue, 34th Floor    New York, New York 10016       (212) 697-1111
  
  --------------------------------------------------------------------------------
  2(a) NAME OF PERSON FOR WHOSE  (b) SOCIAL SECURITY         (c) RELATIONSHIP
       ACCOUNT THE SECURITIES        NO. OR IRS IDENT. NO.       TO ISSUER
       ARE TO BE SOLD
  
       LaPenta, Robert V.            ###-##-####              President & CFO
  
  --------------------------------------------------------------------------------
  (d) ADDRESS        STREET              CITY                ZIP CODE
                        c/o L-3 Communications Corporation
                                 600 Third Avenue
                                New York, NY, 10016
  --------------------------------------------------------------------------------
  
  --------------------------------------------------------------------------------
  INSTRUCTION: The person filing this notice should contact the issuer to obtain
  the I.R.S. Identification Number and the SEC File Number.
  --------------------------------------------------------------------------------
  3(a)            (b)                             SEC USE ONLY  (c)                   (d)                   (e)
                     Name and Address of Each     ------------     Number of Shares        Aggregate            Number of Shares
   Title of the      Broker Through Whom the                        or Other Units           Market              or Other Units
     Class of      Securities are to be Offered   Broker-Dealer       To Be Sold             Value                 Outstanding
    Securities     or Each Market Maker who is     File Number
    To Be Sold       Acquiring the Securities                     (See instr. 3(c))     (See instr. 3(d))       (See instr. 3(e))
  ------------------------------------------------------------------------------------------------------------------------------------
  Common Stock     Morgan Stanley                                       300,000            $17,742,000              106,920,648
                   1585 Broadway
                   New York, NY 10036
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  (f)                      (g)
      Approximate               Name of Each
      Date of Sale               Securities
                                  Exchange
   (See instr. 3(f))
    (MO.  DAY  YR.)          (See instr. 3(g))
  ------------------------------------------------------------------------------------------------------------------------------------
       08/13/04                    NYSE
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  
  ------------------------------------------------------------------------------------------------------------------------------------
  TABLE I - SECURITIES TO BE SOLD
  
  Furnish the following information with respect to the acquisition of the
  securities to be sold and with respect to the payment of all or any part of the
  purchase price or other consideration therefor:
  Name of Person
                                                 from Whom Acquired
  Title of   Date You  Nature of                 (If gift, also give date   Amount of             Date of
  the Class  Acquired  Acquisition Transaction   donor acquired)            Securities Acquired   Payment     Nature of Payment
  ------------------------------------------------------------------------------------------------------------------------------------
  Common     4/1/96    Private Transaction       L-3 Communications           2,944,000(1)         4/1/96     Check
  Stock                                          Holdings, Inc.
  ------------------------------------------------------------------------------------------------------------------------------------
  INSTRUCTIONS: If the securities were purchased and full payment therefor was not
                made in cash at the time of purchase, explain in the table or in a
                note thereto the nature of the consideration given. If the
                consideration consisted of any note or other obligation, or if
                payment was made in installments describe the arrangement and
                state when the note or other obligation was discharged in full or
                the last installment paid.
  
                TABLE II - SECURITIES SOLD DURING THE PAST 3 MONTHS
  
  Furnish the following information as to all securities of the issuer sold during
  the past 3 months by the person for whose account the securities are to be sold.
  Amount of     Gross
  Name and Address of Seller         Title of Securities Sold    Date of Sale    Securities    Proceeds
  -------------------------------------------------------------------------------------------------------
  
  -------------------------------------------------------------------------------------------------------
  REMARKS:
  
  In accordance with the procedures described in the Commission's interpretive
  letter to Goldman, Sachs & Co. dated December 20, 1999, this Form 144 is being
  filed in connection with the sale of 300,000 shares of the Common Stock of L-3
  Communications Holdings, Inc. to Morgan Stanley pursuant to a Variable Prepaid
  Forward Contract. The final pricing terms of the Variable Prepaid Forward
  Contract will be determined by the average sales price that Morgan Stanley will
  be able to obtain for an equivalent number of shares of L-3 Communications
  Holdings, Inc. Common Stock.
  
  (1) As adjusted for two-for-one stock split announced on April 23, 2002.
  
  INSTRUCTIONS:
  
  See the definition of "person" in paragraph (a) of Rule 144. Information is to
  be given not only as to the person for whose account the securities are to be
  sold but also as to sales by all persons whose sales are required by paragraph
  (e) of Rule 144 to be aggregated with sales for the account of the person filing
  this notice.
  
  ATTENTION:
  
  The person for whose account the securities to which this notice relates are to
  sold hereby represents by signing this notice that he does not know any material
  adverse information in regard to the current and prospective operations of the
  Issuer of the securities to be sold which have not been publicly disclosed.
  
  Date: 08/13/2004                     /s/ Robert V. LaPenta
        ------------------              ------------------------------------------
  
  The notice shall be signed by the person for whose account the securities are to
  be sold. At least one copy of the notice shall be manually signed. Any copies
  not manually signed shall bear typed or printed signatures.
  
  ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSION OF FACTS CONSTITUTE FEDERAL
  CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001).