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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            -------------------------
                                  SCHEDULE TO/A
                             TENDER OFFER STATEMENT
    UNDER SECTION 14(D)(1) OR 13(E)(1) OF THE SECURITIES EXCHANGE ACT OF 1934

                                 AMENDMENT NO. 1
                            -------------------------
                                    LASMO PLC
                            (NAME OF SUBJECT COMPANY)
                            -------------------------
                            AMERADA HESS CORPORATION
                            (NAMES OF FILING PERSONS)

                           ORDINARY SHARES OF 25P EACH
                           AMERICAN DEPOSITARY SHARES
                         (TITLE OF CLASS OF SECURITIES)

                           G53831106: ORDINARY SHARES
                      501730204: AMERICAN DEPOSITARY SHARES
                    ----------------------------------------
                      (CUSIP NUMBER OF CLASS OF SECURITIES)
                            -------------------------
                           J. BARCLAY COLLINS II, ESQ.
                  EXECUTIVE VICE PRESIDENT AND GENERAL COUNSEL
                            AMERADA HESS CORPORATION
                           1185 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10036
                                 (212) 997-8500
            (NAME, ADDRESS AND TELEPHONE NUMBER OF PERSON AUTHORIZED
       TO RECEIVE NOTICES AND COMMUNICATIONS ON BEHALF OF FILING PERSONS)
                            -------------------------
                                   COPIES TO:
                            TIMOTHY B. GOODELL, ESQ.
                                WHITE & CASE LLP
                           1155 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10036
                                 (212) 819-8200


|_|  Checkthe box if the filing  relates  solely to  preliminary  communications
     made before the commencement of a tender offer.

Check the  appropriate  boxes below to designate any  transactions  to which the
statement relates:

|X|  third-party tender offer subject to Rule 14d-1.

|_|  issuer tender offer subject to Rule 13e-4.

|_|  going-private transaction subject to Rule 13e-3.

|X|  amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results
of the tender offer: |_|
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     This Amendment No. 1 amends and  supplements  the Tender Offer Statement on
Schedule TO ("Schedule TO") filed on December 13, 2000, relating to the offer by
Amerada Hess Corporation ("Amerada Hess"), a Delaware  corporation,  to purchase
(i) all issued  and to be issued  ordinary  shares of 25 pence each (the  "LASMO
Shares") of LASMO plc ("LASMO") on the basis of  (pound)98.29  in cash and 1 new
share  of  Amerada  Hess for  every  78.7  LASMO  Shares  and (ii) all  American
Depositary Shares of LASMO, each  representing  three LASMO Shares ("ADSs"),  on
the basis of  (pound)294.87  in cash and 3 new shares of Amerada  Hess for every
78.7 ADSs,  upon the terms and subject to the  conditions set forth in the Offer
Document,  dated  December 13, 2000 (the "Offer  Document"),  and in the related
Letter of Transmittal and Form of Acceptance  (which, as they may be amended and
supplemented from time to time, together constitute the "Offer").

ITEM 11.  ADDITIONAL INFORMATION.

     On  December  21,  2000,  Amerada  Hess issued a press  release  noting the
announcement  by ENI S.p.A.  of its  intention  to make a cash offer for all the
issued ordinary  shares of LASMO.  While reserving the right to revise the terms
of the Offer in the event of changed circumstances, Amerada Hess does not intend
to revise the terms of the Offer. A copy of the press release is attached hereto
as Exhibit (a)(11) and is incorporated herein by reference.

ITEM 12.  EXHIBITS.

     Item 12 is hereby amended and supplemented by adding the following:

     Exhibit (a)(11) Press Release by Amerada Hess dated December 21, 2000.






                                    SIGNATURE

     After due inquiry  and to the best of my  knowledge  and belief,  I certify
that the information set forth in this statement is true, complete and correct.

Dated: December 21, 2000
                                          AMERADA HESS CORPORATION


                                          By: /s/ J. Barclay Collins II
                                             --------------------------
                                             Name:  J. Barclay Collins II
                                             Title: Executive Vice President and
                                                    General Counsel

Exhibit (a)(11)

NEWS RELEASE
AMERADA HESS CORPORATION  1185 AVENUE OF THE AMERICAS, N.Y., N.Y., 10036


                                                          FOR IMMEDIATE RELEASE
                                                          ---------------------

         New York, New York .........December 21,  2000.............Amerada Hess
Corporation  notes the announcement by ENI of its intention to make a cash offer
for all the  issued  ordinary  shares  of LASMO  PLC at a price of 200 pence per
ordinary  share.  While  Amerada Hess reserves all rights to revise the terms of
its offer in the event of changed circumstances, Amerada Hess does not intend to
revise the terms of its cash and stock offer for LASMO PLC.



          Contact: Amerada Hess Corporation............C.T. Tursi (212) 536-8593