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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 ---------------

                                 AMENDMENT NO. 1
                                       TO
                                 SCHEDULE 14D-9
                                 (RULE 14d-101)

               SOLICITATION/RECOMMENDATION STATEMENT UNDER SECTION
                 14(d)(4) OF THE SECURITIES EXCHANGE ACT OF 1934

                             MERCATOR SOFTWARE, INC.
                            (Name of Subject Company)

                             MERCATOR SOFTWARE, INC.
                      (Name of Person(s) Filing Statement)

                     COMMON STOCK, PAR VALUE $0.01 PER SHARE
           (INCLUDING THE ASSOCIATED PREFERRED STOCK PURCHASE RIGHTS)
                         (Title of Class of Securities)

                                    587587106
                      (CUSIP Number of Class of Securities)

                                 ---------------

                                   ROY C. KING
                 CHAIRMAN, CHIEF EXECUTIVE OFFICER AND PRESIDENT
                             MERCATOR SOFTWARE, INC.
                                 45 DANBURY ROAD
                                WILTON, CT 06897
                            TELEPHONE: (203) 761-8600
 (Name, address and telephone number of person authorized to receive notice and
           communication on behalf of the person(s) filing statement)

                                    Copy to:

                             MICHAEL WEINSIER, ESQ.
                           CHARLES A. SAMUELSON, ESQ.
                      JENKENS & GILCHRIST PARKER CHAPIN LLP
                              405 LEXINGTON AVENUE
                            NEW YORK, NEW YORK 10174
                            TELEPHONE: (212) 704-6000

[ ]   Check the box if the filing relates solely to preliminary communications
      made before the commencement of a tender offer.


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      This Amendment No. 1 to Schedule 14D-9 amends and supplements the Schedule
14D-9 (the "Schedule 14D-9") initially filed with the Securities and Exchange
Commission on August 8, 2003 by Mercator Software, Inc., a Delaware corporation
("Mercator"), relating to a tender offer commenced by Greek Acquisition
Corporation, a Delaware corporation and a wholly-owned subsidiary of Ascential
Software Corporation, a Delaware corporation, on August 8, 2003 to purchase all
of the outstanding shares of Mercator's common stock, par value $0.01 per share,
together with the associated preferred stock purchase rights, for $3.00 per
share, net to the seller in cash, without interest thereon. Capitalized terms
used but not defined herein have the meanings assigned to them in the Schedule
14D-9.

      The information in the Schedule 14D-9 is hereby expressly incorporated
herein by reference, except as otherwise set forth below.

ITEM 9. EXHIBITS

      Item 9 of Schedule 14D-9 is hereby amended and supplemented by adding the
following exhibit (filed herewith):



EXHIBIT
  NO.                                 DESCRIPTION
-------                               -----------
           
 (e)(15)      Memorandum dated August 19, 2003 to Mercator's employees regarding
              tendering shares and stock option information



                                       1

                                    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: August 19, 2003

                                         MERCATOR SOFTWARE, INC.


                                         By:   /s/ Roy C. King
                                            ------------------------------------
                                               Roy C. King
                                               Chairman of the Board of
                                               Directors, Chief Executive
                                               Officer and President