<PAGE>
                                                                  EXHIBIT 10.23a

                           AMENDMENT NO. 1 AND CONSENT

         THIS AMENDMENT NO. 1 AND CONSENT is being executed and delivered as of
January 12, 2004, by and among Chicago Bridge and Iron Company N.V., a
corporation organized under the laws of the Kingdom of the Netherlands (the
"Company"), certain Subsidiaries party thereto as Borrowers (the "Subsidiary
Borrowers"), Bank One, NA as Administrative Agent (the "Administrative Agent")
under the hereinafter identified and defined Credit Agreements and the lenders
party to said Credit Agreements. All capitalized terms used herein without
definition shall have the same meanings as set forth in the hereinafter
identified and defined Three-Year Credit Agreement.

                                   WITNESSETH:

                  WHEREAS, the Company, the Subsidiary Borrowers, the Lenders
and the Administrative Agent are currently party to that certain Three-Year
Credit Agreement dated as of August 22, 2003 (as the same may be amended,
restated, supplemented or otherwise modified from time to time, the "Three-Year
Credit Agreement"), and that certain Five-Year Credit Agreement dated as of
August 22, 2003 (as the same may be amended, restated, supplemented or otherwise
modified from time to time, the "Five-Year Credit Agreement," and, together with
the Three-Year Credit Agreement, the "Credit Agreements");

                  WHEREAS, certain Subsidiaries of the Company desire to enter
into a transaction pursuant to which a Subsidiary Guarantor will make an
intercompany unsecured loan in an amount not to exceed $60,000,000 to Horton
CBI, Limited (the "Horton Transaction");

                  WHEREAS, the Company has informed the Administrative Agent and
the Lenders of certain proposed transactions pursuant to which (in no particular
order) (i) certain purchasers, which may include members of the current
management teams of Callidus Technologies, L.L.C. and Callidus Technologies
International, L.L.C. (together, "Callidus") with an aggregate book value not in
excess of $12,000,000, acquire Callidus from the Company pursuant to a
transaction to be consummated on or before June 30, 2004 (the "Callidus Sale"),
(ii) Callidus enters into, and obtains extensions of credit under, a secured
credit facility with Bank of Oklahoma N.A. in an aggregate principal amount not
to exceed $10,000,000 (the "Callidus Credit Facility"), (iii) Callidus grants
liens and security interests over all or substantially all of the assets and
properties of Callidus to secure its obligations and liabilities under the
Callidus Credit Facility, (iv) Bank of Oklahoma N.A. is permitted to issue
letters of credit under the Callidus Credit Facility on behalf of Callidus as an
account party ("Callidus L/Cs") so long as the Callidus Sale has not been
consummated and, notwithstanding such consummation, Callidus L/Cs issued prior
to the consummation of the Callidus Sale shall be treated as additional
Indebtedness and Contingent Obligations permitted under the Credit Agreements,
and (v) substantially concurrently with the consummation of the Callidus Sale,
Callidus shall be released from its obligations under the Subsidiary Guaranty
and following such release neither Callidus Technologies, L.L.C. nor Callidus
Technologies International, L.L.C. shall be deemed to be a Subsidiary or a
Subsidiary Guarantor (the foregoing transactions and

<PAGE>


events as described in this paragraph being referred to collectively as the
"Callidus Transaction," and, together with the Horton Transaction, the
"Transactions");

                  WHEREAS, the Company has requested that, notwithstanding
anything contained in the Credit Agreements, the Lenders consent (the "Consent")
to such Subsidiaries' consummation of the Transactions; and

                  WHEREAS, the Lenders party hereto are willing to grant the
Consent on the terms and conditions stated herein;

                  WHEREAS, the Borrowers also have requested the Lenders and the
Agent to amend the Credit Agreements in certain other respects;

                  WHEREAS, the Lenders and the Agent have agreed to amend the
Credit Agreements on the terms and conditions set forth in section 2 hereof.

                  NOW, THEREFORE, in consideration of the foregoing premises,
the terms and conditions stated herein and other valuable consideration, the
receipt and sufficiency of which are hereby acknowledged by the Borrowers and
the Lenders, such parties hereby agree as follows:

                  1. Consent. The Lenders hereby grant the Consent.

                  2. Amendment. Each Credit Agreement shall be and hereby is
amended as follows:

                  (a)      Section 1.1 is amended to insert the following new
                           defined terms thereto:

                           "Callidus" is defined in the First Amendment.

                           "Callidus Credit Facility" is defined in the First
                           Amendment.

                           "Callidus L/Cs" is defined in the First Amendment.

                           "Callidus Sale" is defined in the First Amendment.

                           "First Amendment" means that certain Amendment No. 1
                           and Consent dated as of January 12, 2004 by and among
                           the Borrowers, the Lenders party thereto and the
                           Administrative Agent.

                  (b)      The word "and" is deleted from the end of Section
                           7.3(A)(viii).

                  (c)      Section 7.3(A) is amended to insert a new section
                           (ix) as follows:

                           (ix) Indebtedness in an aggregate principal amount
                           not in excess of $10,000,000 incurred as the direct
                           result of the issuance of the Callidus L/Cs; and

                  (d)      The former Section 7.3(A)(ix) is renumbered as
                           Section 7.3(A)(x).

<PAGE>


                  (e)      The word "and" is deleted from the end of Section
                           7.3(B)(v).

                  (f)      Section 7.3(B) is amended to insert a new section
                           (vi) as follows:

                           (vi)  The Callidus Sale; and

                  (g)      The former Section 7.3(B)(vi) is renumbered as
                           Section 7.3(B)(vii).

                  (h)      Section 7.3(B)(vii) is amended to change the
                           reference to "clauses (i) through (v) above" to
                           "clauses (i) through (vi) above."

                  (i)      Section 7.3(C) is amended to insert a new section
                           (iv) as follows:

                           (iv) Liens granted by Callidus Technologies, L.L.C.
                           or Callidus Technologies International, L.L.C. to
                           secure the Indebtedness permitted by Section
                           7.3(A)(ix) in connection with the issuance of the
                           Callidus L/Cs;

                  (j)      The former Section 7.3(C)(iv) is renumbered as
                           Section 7.3(C)(v).

                  (k)      Section 7.3(D) is amended to insert a new Section (x)
                           as follows:

                           (x) Investments resulting from the acceptance of
                           noncash consideration as a portion of the purchase
                           price from the Callidus Sale;

                  (l)      The former Section 7.3(D)(x) is renumbered as Section
                           7.3(D)(xi).

                  (m)      Section 7.3(E) is amended to delete the word "and"
                           before the letters "(iv)" and to add the following
                           language at the end:

                           and (v) Contingent Obligations consisting of
                           Indebtedness permitted by Section 7.3(A)(ix)
                           resulting from the issuance of the Callidus L/Cs.

                  3. Conditions of Effectiveness. This Consent and Amendment
shall be deemed to have become effective as of the date hereof, but such
effectiveness shall be subject to the following conditions: (i) the
Administrative Agent shall have received executed counterparts of this Consent
duly executed and delivered by the Company, the Subsidiary Borrowers and the
"Required Lenders" (under each of the Credit Agreements) and executed
counterparts of the Reaffirmation attached hereto duly executed and delivered by
the Subsidiary Guarantors; (ii) the indebtedness evidenced by the intercompany
loan under the Horton Transaction shall be expressly subordinate to the payment
in full in cash of the Obligations on terms satisfactory to the Administrative
Agent; (iii) the terms and conditions of each above-described component of the
Callidus Transaction, if consummated, shall be satisfactory to the
Administrative Agent at the time of such consummation; (iv) the Company shall
have paid to the Administrative Agent, for the ratable benefit of each Lender
which has delivered to the Administrative Agent or the

<PAGE>


Administrative Agent's counsel its executed signature page hereto by such time
as is required by the Administrative Agent, an amendment fee of $2,500 for each
such consenting Lender and (v) no Default or Unmatured Default shall have
occurred and remain unwaived or uncured.

                  4. Representation and Warranties. Each Borrower hereby
represents and warrants that (i) all of the representations and warranties
contained in Article VI of each Credit Agreement are true and correct and (ii)
no Default or Unmatured Default is in effect.

                  5. No Implicit Waiver. Except as expressly set forth herein,
(i) the execution, delivery and effectiveness of this Amendment No. 1 and
Consent shall neither operate as a waiver of any rights, power or remedy of the
Administrative Agent or the Lenders under the Credit Agreements or any other
documents executed in connection with the Credit Agreements, nor constitute a
waiver of any provision of the Credit Agreements nor any other document executed
in connection therewith and (ii) the Credit Agreements shall remain in full
force and effect in accordance with their original terms.

                  6. GOVERNING LAW. THE ADMINISTRATIVE AGENT ACCEPTS THIS
AMENDMENT NO. 1 AND CONSENT, ON BEHALF OF ITSELF AND THE LENDERS, AT CHICAGO,
ILLINOIS BY ACKNOWLEDGING AND AGREEING TO IT THERE. ANY DISPUTE BETWEEN ANY
BORROWER AND THE ADMINISTRATIVE AGENT OR ANY LENDER ARISING OUT OF, CONNECTED
WITH, RELATED TO, OR INCIDENTAL TO THE RELATIONSHIP ESTABLISHED BETWEEN THEM IN
CONNECTION WITH, THIS CONSENT AND AMENDMENT, THE CREDIT AGREEMENTS OR ANY OF THE
OTHER LOAN DOCUMENTS, AND WHETHER ARISING IN CONTRACT, TORT, EQUITY, OR
OTHERWISE, SHALL BE RESOLVED IN ACCORDANCE WITH THE INTERNAL LAWS (INCLUDING
SECTION 735 ILCS 105/5-1 ET SEQ. BUT OTHERWISE WITHOUT REGARD TO THE CONFLICTS
OF LAWS PROVISIONS) OF THE STATE OF ILLINOIS.



<PAGE>


         IN WITNESS WHEREOF, this Amendment No. 1 and Consent has been duly
executed as of the day and year first above written.


                                      CHICAGO BRIDGE & IRON COMPANY N.V., as the
                                      Company
                                      By: CHICAGO BRIDGE & IRON COMPANY B.V.
                                      Its: Managing Director



                                      By:
                                          --------------------------------------
                                      Name: Gerald M. Glenn
                                      Title: Managing Director




    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003

<PAGE>




                                      CHICAGO BRIDGE & IRON COMPANY
                                      (DELAWARE), as a Subsidiary Borrower


                                    By:
                                       ----------------------------------------
                                    Name: Richard A. Byers
                                    Title: Vice President and Treasurer


                                    CB&I TYLER COMPANY, as a Subsidiary Borrower


                                    By:
                                       ----------------------------------------
                                    Name: Richard A. Byers
                                    Title: Vice President and Treasurer


                                    CBI SERVICES, INC., as a Subsidiary Borrower


                                    By:
                                       ----------------------------------------
                                    Name: Terrence G. Browne
                                    Title: Treasurer


                                    CB&I CONSTRUCTORS, INC., as a Subsidiary
                                    Borrower

                                    By:
                                       ----------------------------------------
                                    Name: Richard A. Byers
                                    Title: Vice President and Treasurer



    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003



<PAGE>


                                    BANK ONE, NA (having its principal office in
                                    Chicago, Illinois), as Administrative Agent
                                    and as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    BANK OF AMERICA, N.A., as Syndication Agent
                                    and as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    BANK OF MONTREAL, as a Documentation Agent
                                    and as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    CREDIT SUISSE FIRST BOSTON, ACTING THROUGH
                                    ITS CAYMAN ISLANDS BRANCH, as a
                                    Documentation Agent and as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:




    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003


<PAGE>


                                    WELLS FARGO BANK TEXAS, N.A., as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    BNP PARIBAS, as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


                                    FORTIS CAPITAL CORP., as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    SOUTHWEST BANK OF TEXAS, N.A., as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    WASHINGTON MUTUAL BANK, as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003

<PAGE>



                                    THE NORTHERN TRUST COMPANY, as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


                                    KEYBANK NATIONAL ASSOCIATION, as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


                                    JPMORGAN CHASE BANK, as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


                                    REGIONS BANK, as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


                                    ALLIED IRISH BANK, PLC, as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003

<PAGE>



                                    STANDARD CHARTERED BANK, as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


                                    HIBERNIA NATIONAL BANK, as a Lender



                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    LEHMAN COMMERCIAL PAPER INC., as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:



                                    ARAB BANKING CORPORATION, as a Lender


                                    By:
                                       ----------------------------------------
                                    Name:
                                    Title:


    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003


<PAGE>

                                  REAFFIRMATION

                  Each of the undersigned hereby acknowledges receipt of a copy
of the foregoing Amendment No. 1 and Consent in connection with that certain
Three-Year Credit Agreement dated as of August 22, 2003 (as the same may be
amended, restated, supplemented or otherwise modified from time to time, the
"Three-Year Credit Agreement"), and that certain Five-Year Credit Agreement
dated as of August 22, 2003 (as the same may be amended, restated, supplemented
or otherwise modified from time to time, the "Five-Year Credit Agreement," and,
together with the Three-Year Credit Agreement, the "Credit Agreements") by and
among Chicago Bridge and Iron Company N.V. (the "Company"), certain Subsidiaries
of the Company party thereto as Borrowers (the "Subsidiary Borrowers"), Bank
One, NA as Administrative Agent (the "Administrative Agent") under the Credit
Agreements and the lenders party to said Credit Agreements, which Amendment No.
1 and Consent is dated as of January 12, 2004 (the "Amendment and Consent").
Capitalized terms used in this Reaffirmation and not defined herein shall have
the meanings given to them in the Three-Year Credit Agreement. Without in any
way establishing a course of dealing by the Administrative Agent or any Lender,
each of the undersigned consents to the Amendment and Consent and reaffirms the
terms and conditions of the Guaranty and any other Loan Document executed by it
and acknowledges and agrees that such agreement and each and every such Loan
Document executed by the undersigned in connection with the Credit Agreements
remains in full force and effect and is hereby reaffirmed, ratified and
confirmed. All references to the Credit Agreements contained in the
above-referenced documents shall be a reference to the Credit Agreements as so
modified by the Amendment and Consent and as the same may from time to time
hereafter be amended, modified or restated.

CHICAGO BRIDGE & IRON COMPANY N.V.
By: CHICAGO BRIDGE & IRON COMPANY B.V.
Its: Managing Director



By
   --------------------------------
Name: Gerald M. Glenn
Title: Managing Director

CHICAGO BRIDGE & IRON COMPANY

By
   --------------------------------
Name: Richard A. Byers
Title: Vice President and Treasurer


    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003

<PAGE>



CHICAGO BRIDGE & IRON COMPANY (DELAWARE)

By
   --------------------------------
Name: Richard A. Byers
Title: Vice President and Treasurer

CB&I TYLER COMPANY

By
   --------------------------
Name: Richard A. Byers
Title: Vice President and Treasurer

CB&I CONSTRUCTORS, INC.


By
   --------------------------------
Name: Richard A. Byers
Title: Vice President and Treasurer

CBI SERVICES, INC.


By
   --------------------------------
Name: Terrence G. Browne
Title: Treasurer



    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003

<PAGE>


HORTON CBI, LIMITED

By
   --------------------------------
Name: James W. House
Title: Treasurer


CBI VENEZOLANA, S.A.

By
   --------------------------------
Name: Mario D. Marquez
Title: Vice President


CBI EASTERN ANSTALT

By
   --------------------------------
Name: Alan R. Black
Title: Administrator


CBI CONSTRUCTORS PTY, LTD.

By
   --------------------------------
Name: Vassily J. Calligeros
Title: Director


LEALAND FINANCE COMPANY B.V.

By
   --------------------------------
Name: Timothy J. Moran
Title: Managing Director


CB&I (EUROPE) B.V.

By
   --------------------------------
Name: Ray Buckley
Title: Director



    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003



<PAGE>
ARABIAN GULF MATERIAL SUPPLY COMPANY, LTD.

By
   --------------------------------
Name: Alan R. Black
Title: Vice President


ASIA PACIFIC SUPPLY CO.

By
   --------------------------------
Name: Timothy J. Moran
Title: Treasurer


CBI COMPANY LTD.

By
   --------------------------------
Name: Richard A. Byers
Title: Treasurer


CBI CONSTRUCCIONES S.A.

By
   --------------------------------
Name: Antonio Medic
Title: Director


CBI CONSTRUCTORS LIMITED

By
   --------------------------------
Name: Ray Buckley
Title: Director


CBI HOLDINGS (U.K.) LIMITED

By
   --------------------------------
Name: Ray Buckley
Title: Director



    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003

<PAGE>


CBI OVERSEAS, LLC

By
   --------------------------------
Name: Wong Keem Ming
Title: Treasurer


CENTRAL TRADING COMPANY, LTD.

By
   --------------------------------
Name: Timothy J. Moran
Title: Treasurer


CHICAGO BRIDGE & IRON (ANTILLES) N.V.

By
   --------------------------------
Name: Gerald M. Glenn
Title: Managing Director


CHICAGO BRIDGE & IRON COMPANY B.V.

By
   --------------------------------
Name: Gerald M. Glenn
Title: Managing Director


CMP HOLDINGS B.V.

By
   --------------------------------
Name: Ray Buckley
Title: Director


PACIFIC RIM MATERIAL SUPPLY COMPANY, LTD.

By
   --------------------------------
Name: Alan R. Black
Title: Vice President



    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003


<PAGE>

HOWE-BAKER INTERNATIONAL, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President and CEO


HOWE-BAKER ENGINEERS, LTD.
By and through its General Partner,
Howe-Baker Management, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President


HOWE-BAKER HOLDINGS, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President and CEO


HOWE-BAKER MANAGEMENT, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President


HOWE-BAKER, L.P.
By and through its General Partner,
Howe-Baker Management, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President


    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003


<PAGE>


MATRIX ENGINEERING, LTD.
By and through its General Partner,
Matrix Management Services, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: Chairman of the Board and CEO


HBI HOLDINGS, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President and CEO


HOWE-BAKER INTERNATIONAL MANAGEMENT, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: Chairman of the Board and CEO


A&B BUILDERS, LTD.
By and through its General Partner,
Matrix Management Services, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: Chairman of the Board and CEO


MATRIX MANAGEMENT SERVICES, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: Chairman of the Board and CEO


    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003


<PAGE>



CALLIDUS TECHNOLOGIES INTERNATIONAL, L.L.C.

By
   --------------------------------
Name: W. P. Bartlett
Title: President and CEO


CALLIDUS TECHNOLOGIES, L.L.C.

By
   --------------------------------
Name: W. P. Bartlett
Title: President and CEO


CONSTRUCTORS INTERNATIONAL, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President and CEO


TPA HOWE-BAKER, LTD.
By and through its General Partner,
Howe-Baker Management, L.L.C.

By
   --------------------------------
Name: James R. McAdory III
Title: President


SOUTHERN TROPIC MATERIAL SUPPLY COMPANY, LTD.

By
   --------------------------------
Name: Alan R. Black
Title: Director


CB&I (NIGERIA) LIMITED

By
   --------------------------------
Name: John R. Edmonds
Title: Director


    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003

<PAGE>


CHICAGO BRIDGE & IRON (ESPANA) S.A.

By
   --------------------------------
Name: Ray Buckley
Title: Director


CBI (PHILLIPINES), INC.

By
   --------------------------------
Name: Timothy J. Moran
Title: Treasurer


CB&I JOHN BROWN LIMITED

By
   --------------------------------
Name: Ian Corbidge
Title: Managing Director


MORSE CONSTRUCTION GROUP, INC.

By
   --------------------------------
Name: Terrence G. Browne
Title: Treasurer


CBI HUNGARY HOLDING LIMITED LIABILITY COMPANY

By
   --------------------------------
Name: Ray Buckley
Title: Managing Director



    Signature Page to Amendment No. 1 and Consent dated as of January 2004 to
                    Chicago Bridge & Iron Company N.V. et al
           Three-Year Credit Agreement and Five-Year Credit Agreement
                           dated as of August 22, 2003