UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549



                                   FORM 8-K


                                CURRENT REPORT
    Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934


     Date of Report (Date of earliest event reported): September 12, 2003


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


        Delaware                        0-15325                94-3011736
(State or other jurisdiction    (Commission File Number)   (IRS Employer
 of incorporation)                                         Identification No.)


            50 Washington Street, Westborough, Massachusetts 01581
              (Address of principal executive offices) (zip code)


      Registrant's telephone number, including area code: (508) 366-3888


                                Not Applicable
         (Former name or former address, if changed since last report)





Item 2.  Acquisition or Disposition of Assets.

         On September 12, 2003, Ascential Software Corporation, a Delaware
corporation ("Ascential"), completed its acquisition of Mercator Software,
Inc., a Delaware corporation ("Mercator"). The acquisition was made pursuant
to an Agreement and Plan of Merger, dated as of August 2, 2003 (the "Merger
Agreement"), by and among Ascential, Greek Acquisition Corporation, a Delaware
corporation and wholly owned subsidiary of Ascential ("Merger Sub") and
Mercator.

         Pursuant to the Merger Agreement, Ascential, through Merger Sub,
commenced a tender offer (the "Offer") for all outstanding shares of common
stock, par value $0.01 per share, of Mercator (the "Shares") at $3.00 per
share in cash, without interest thereon. Following expiration of the Offer on
September 11, 2003, Ascential accepted for payment the Shares tendered and
exercised an option (the "Option") granted to it by Mercator for 19.99% of the
then outstanding common stock of Mercator. As a result of the purchase of the
Shares and the exercise of the Option, Ascential, through Merger Sub, owned
more than 90% of the Shares of Mercator.

         On September 12, 2003, Ascential effected a short form merger (the
"Merger") whereby Mercator was merged with and into Merger Sub, with Mercator
surviving as a wholly owned subsidiary of Ascential. In the Merger, each
outstanding Share (other than (i) Shares owned by Ascential, Merger Sub or the
Company or their respective subsidiaries, and (ii) Shares that are held by
stockholders, if any, who properly exercise their appraisal rights under the
DGCL), were converted into the right to receive $3.00 per share in cash,
without interest thereon. In addition, all outstanding options to purchase
Shares granted pursuant to the TSI International Software Ltd. 1993 Stock
Option Plan, the 1996 Novera Software Inc. Stock Option Plan and the Mercator
Software, Inc. 1998 Equity Incentive Plan were converted into options to
purchase shares of common stock, par value $.01 per share, of Ascential,
subject to certain adjustments. The description of the transactions
contemplated by the Merger Agreement is qualified in its entirety by reference
to the full text of the Merger Agreement, which is filed at Exhibit 2.1 hereto
and incorporated by reference herein.

         The aggregate purchase price for all of the Shares of Mercator was
approximately $109 million in cash. The purchase price was funded by
Ascential's working capital.

Item 7.  Financial Statements and Exhibits

         (a) Financial Statements.

         It is impracticable for Ascential to file herewith the required
financial statements in this Current Report on Form 8-K. The financial
statements of Mercator required by this item will be filed by amendment to
this Current Report on Form 8-K as soon as practicable, but no later than 60
days after the date this Current Report on Form 8-K is required to be filed.

         (b) Pro Forma Financial Information

         It is impracticable for Ascential to file herewith the required pro
forma financial information in this Current Report on Form 8-K. The pro forma
financial information required by this item will be filed by amendment to this
Current Report on Form 8-K as soon as practicable, but no later than 60 days
after the date this Current Report on Form 8-K is required to be filed.

         (c) Exhibits.

         Exhibit
           No.             Exhibit
           ---             -------

         2.1             Agreement and Plan of Merger, dated as of August 2,
                         2003, by and among Ascential Software Corporation,
                         Greek Acquisition Corporation and Mercator Software,
                         Inc. (incorporated herein by reference to Exhibit 2.1
                         to the Current Report on Form 8-K filed by Ascential
                         on August 5, 2003).






                                  SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.


                                             ASCENTIAL SOFTWARE CORPORATION
                                             (Registrant)

Date: September 26, 2003                     /s/ Peter Fiore
                                             --------------------------------
                                             By:  Peter Fiore
                                                  President







                                 EXHIBIT INDEX

      Exhibit
        No.               Exhibit
        ---               -------

         2.1             Agreement and Plan of Merger, dated as of August 2,
                         2003, by and among Ascential Software Corporation,
                         Greek Acquisition Corporation and Mercator Software,
                         Inc. (incorporated herein by reference to Exhibit 2.1
                         to the Current Report on Form 8-K filed by Ascential
                         on August 5, 2003).