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                                                                   EXHIBIT 10.55

                   SECOND AMENDMENT TO STOCKHOLDERS AGREEMENT

     This SECOND AMENDMENT TO STOCKHOLDERS AGREEMENT (this "Amendment") is made
this ninth day of February, 2000, by and among ZEFER Corp., a Delaware
corporation (the "Company") and GTCR Fund VI, L.P., a Delaware limited
partnership ("GTCR"). Any capitalized term used in this Amendment which is not
otherwise defined herein shall have the meaning assigned to such term in the
Stockholders Agreement (as defined below).

     WHEREAS, the Company and GTCR are parties to that certain Stockholders
Agreement, dated as of March 23, 1999 (as amended and modified from time to
time), by and among the Company, GTCR and certain other stockholders of the
Company (the "Stockholders Agreement");

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Company and GTCR agree as
follows:

     1.   Section 1(a)(i) of the Stockholders Agreement in hereby amended and
          restated in its entirety to read as follows:

          (i)  the authorized number of directors on the Company's board of
               directors (the "Board") shall be established at nine directors.

     2.   Section 1(a)(ii) of the Stockholders Agreement in hereby amended and
          restated in its entirety to read as follows:

          (ii) the following persons shall be elected to the Board:

               (A)  until the later to occur of (i) such time as GTCR Capital
                    Partners, L.P. ("GTCR Capital") no longer holds any capital
                    stock (or securities exercisable or convertible into capital
                    stock) of the Company and (ii) such time as no Loan
                    Obligation (as defined in Section 12 of the Loan Agreement)
                    is outstanding, two representatives designated by GTCR and
                    one representative designated by GTCR Capital; and
                    thereafter, three representatives designated by GTCR
                    (collectively, and regardless of whether designated by GTCR
                    or GTCR Capital, the "Investor Directors");

               (B)  William Seibel and one additional Executive of the Company
                    designated by the Company's chief executive officer (the
                    "CEO") (each, an "Executive Director" and collectively, the
                    "Executive Directors"); and

               (C)  four representatives chosen jointly by GTCR and the CEO (the
                    "Outside Directors"); provided that no Outside Directors
                    shall be a member of the Company's management or an employee
                    or officer of the Company or its subsidiaries; provided
                    further that if GTCR and the CEO are unable to agree on the
                    Outside Directors within 10 days after the date specified by
                    GTCR for electing the Outside Directors, then GTCR, in its
                    sole discretion, shall designate the Outside Directors;

     3.   Other than as specifically provided herein, the Stockholders
          Agreement, as amended hereby, shall remain in full force and effect,
          and is hereby ratified and confirmed in all respects.

     4.   As required by Section 10 of the Stockholders Agreement, the Company
          and GTCR hereby consent to this Amendment.

     5.   This Amendment may be executed in two or more counterparts, each of
          which shall for all purposes be deemed to be an original and all of
          which shall constitute the same instrument.

                                     * * * *
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            IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be executed on the day and year first above written.


                                     ZEFER CORP.

                                     By:    /s/ James Slamp
                                           -----------------------------
                                     Its:
                                           -----------------------------


                                     GTCR FUND VI, L.P.

                                     By:   GTCR Partners VI, L.P.
                                     Its:  General Partner

                                     By:   GTCR Golder Rauner, LLC
                                     Its:  General Partner

                                     By:    /s/ Philip Canfield
                                        -----------------------------
                                     Its:  Principal



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