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                                                                    EXHIBIT 10.6

                                    AMENDMENT
                                       TO
                      AMENDED AND RESTATED CREDIT AGREEMENT

                  This AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT (this
"Amendment"), effective as of July 22, 1999, is entered into by and among CORE
LABORATORIES N.V., a Netherlands limited liability company (the "Parent"), CORE
LABORATORIES, INC., a Delaware corporation (the "US Borrower" and together with
the Parent the "Borrowers"), the Subsidiaries of the Borrowers (together with
their respective successors and assigns) designated under the Credit Agreement
or this Amendment as Guarantors, the banks named on the signature pages hereto
(together with their respective successors and assigns in such capacity, the
"Banks"), BANKERS TRUST COMPANY, as the administrative agent for the Banks
(together with its successors and assigns in such capacity, the "Administrative
Agent"), and BANK OF AMERICA, N.A., successor by merger to NATIONSBANK, N.A., as
the syndication agent for the Banks (together with its successors and assigns in
such capacity, the "Syndication Agent" and, together with the Administrative
Agent, the "Agents"), and as the issuing bank with respect to the Letters of
Credit issued hereunder (together with its successors and assigns in such
capacity, the "Issuing Bank"). Unless otherwise defined herein, all capitalized
terms used herein are as defined in the hereafter-referenced Credit Agreement.

                  WHEREAS, the Borrowers and certain Subsidiaries of the
Borrowers, as Guarantors, the Agents and the Banks have executed that certain
Amended and Restated Credit Agreement dated as of July 18, 1997 (as it may be
amended, extended, supplemented or amended and restated from time to time, the
"Credit Agreement").

                  WHEREAS, pursuant to the Credit Agreement, (a) the Banks
agreed to provide (i) the Parent with a $55,000,000 term loan facility (the
"Tranche A Loan") and the Equivalent in Dutch Guilders of a $5,000,000 revolving
credit facility (the "Guilder Revolving Loans"), (ii) the US Borrower with a
$50,000,000 revolving credit facility providing for letters of credit and
revolving loans (the "Dollar Revolving Loans") and (iii) the UK Borrower with
the Equivalent in Pounds Sterling of a $15,000,000 term loan facility (the
"Tranche B Loan") and (b) the Guilder Swing Line Banks agreed to provide the
Equivalent in Dutch Guilders of a $5,000,000 revolving credit facility (the
"Guilder Swing Line Loan").

                  WHEREAS, in connection with the Credit Agreement, the
Borrowers executed Pledge Agreements granting security interests and liens on
all of the Collateral subject thereto in favor of the Administrative Agent for
the benefit of the Bank Group.

                  WHEREAS, the Borrowers have now requested that (a) the Tranche
A Loan, the Tranche B Loan and the Guilder Swing Line Loan be repaid in full
with a portion of the proceeds of certain Indebtedness described in Section
6.01(g) to be incurred by the U.S. Borrower and to terminate the Commitment of
the relevant Banks to make such Loans, (b) the Total Dollar Revolving Commitment
be increased from $50,000,000 to $95,000,000, (c) that the Guilder Revolving
Loan Bank solely provide the Guilder Revolving Commitment, (d) that a Dollar
Swing Line Loan be



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added and (e) that the Collateral (except for the Subsidiaries' Guaranties)
securing the Obligations be released.

                   WHEREAS, the Banks and the Agents have agreed to do so to the
extent reflected in this Amendment provided that each of the Parent, the US
Borrower and each Guarantor ratifies and confirms all of its respective
obligations under the Credit Agreement and the Loan Documents and agrees to make
certain other amendments as set forth herein.

                  NOW, THEREFORE, in consideration of the premises and for other
good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto hereby agree as follows:

                  1.       Amendments to the Credit  Agreement.  The following
provisions of the Credit Agreement are hereby modified as follows:

                  a.       Section  2.01 - Amendment. (i) Section 2.01(a) is
         hereby deleted in its entirety and the following is substituted
         therefor:

                           "Section 2.01 Commitments. (a) Tranche A Loan. The
                  parties hereby acknowledge and agree that, as of the date of
                  the Amendment, the Banks no longer have any obligation or
                  liability to make any Tranche A Loans (as defined by the
                  Credit Agreement prior to the Amendment) and all Tranche A
                  Loans shall be repaid simultaneously with the execution of the
                  Amendment. Accordingly, the parties further agree that, as of
                  the date of the Amendment, the Tranche A Commitment of each of
                  the Banks is hereby fully, finally and irrevocably terminated.
                  All references in the Credit Agreement to Tranche A Loans and
                  related matters are no longer applicable from the date of the
                  Amendment. Notwithstanding the foregoing, the Parent and the
                  Guarantors shall continue to be liable for the repayment of
                  any Tranche A Loans outstanding until the full and final
                  repayment thereof."

                  (ii) Section 2.01(b) is hereby deleted in its entirety and the
         following is substituted therefore:

                       "(b) Tranche B Loan. The parties hereby acknowledge and
                  agree that, as of the date of the Amendment, the Banks no
                  longer have any obligation or liability to make any Tranche B
                  Loans (as defined by the Credit Agreement prior to the
                  Amendment) and all Tranche B Loans shall be repaid
                  simultaneously with the execution of the Amendment.
                  Accordingly, the parties further agree that, as of the date of
                  the Amendment, the Tranche B Commitment of each of the Banks
                  is hereby fully, finally and irrevocably terminated. All
                  references in the Credit Agreement to Tranche B Loans and
                  related matters are no longer applicable from the date of the
                  Amendment. Notwithstanding the foregoing, the UK Borrower and
                  the Guarantors




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                  shall continue to be liable for the repayment of any Tranche B
                  Loans outstanding until the full and final repayment thereof."

                  (iii) Section 2.01(d) is hereby deleted in its entirety and
         the following is substituted therefor:

                        "(d) Guilder Revolving Loans. The Guilder Revolving
                  Loan Bank agrees, on the terms and conditions hereinafter set
                  forth, to make one or more loans (each a "Guilder Revolving
                  Loan") to the Parent from time to time on any Business Day,
                  from the date of the Amendment up to but excluding the
                  Termination Date, in an aggregate amount outstanding not to
                  exceed the Guilder Revolving Loan Bank's Guilder Revolving
                  Commitment. All Guilder Revolving Loans (i) subject to Section
                  2.13(a) shall be made and repaid in Guilders or Euros, (ii)
                  made and maintained as Eurocurrency Rate Loans and (iii) may
                  be repaid and reborrowed in the same manner as Dollar
                  Revolving Loans."

                  (iv) Section 2.01(e) is hereby deleted in its entirety and the
         following is substituted therefor:

                        "(e) Guilder Swing Line Loans. The parties hereby
                  acknowledge and agree that as of the date of the Amendment the
                  Guilder Swing Line Banks no longer have any obligation or
                  liability to make any Guilder Swing Line Loans (as defined by
                  the Credit Agreement prior to this Amendment) and all Guilder
                  Swing Line Loans shall be repaid simultaneously with the
                  execution of the Amendment. Accordingly, the parties further
                  agree that as of the date of the Amendment each Guilder Swing
                  Line Commitment is hereby fully, finally and irrevocably
                  terminated. All references in the Credit Agreement to Guilder
                  Swing Line Loans and related matters are no longer applicable
                  from the date of the Amendment. Notwithstanding the foregoing,
                  the Parent and the Guarantors shall continue to be liable for
                  the repayment of any Guilder Swing Line Loans outstanding
                  until the full and final repayment thereof."

                  (v) A new Section 2.01(h) is hereby added to read as follows:

                        "(h) Dollar Swing Line Loans. (i) Subject to the terms
                  and conditions hereof, and in substitution for the Dollar
                  Revolving Loans described in Section 2.01(c) above, the
                  Dollar Swing Line Banks agree at any time and from time to
                  time on and after the date of the Amendment and prior to the
                  Termination Date, to make swing line loans (each a "Dollar
                  Swing Line Loan" and collectively, the "Dollar Swing Line
                  Loans") to the US Borrower in an aggregate principal amount
                  at any one time outstanding not to exceed $10,000,000. The
                  Dollar Swing Line Loans shall be made and maintained as Base
                  Rate Loans and as part of a single Borrowing made by the
                  Dollar Swing Line Banks on the same day ratably according to
                  their respective Commitment Percentages for Dollar Swing
                  Line Loans. Each Borrowing




                                      -3-
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                  of Dollar Swing Line Loans shall be in an aggregate amount not
                  less than $1,000,000 and in an integral multiple of $200,000
                  in excess thereof. Within the limits set forth above and
                  subject to the terms and conditions of this Agreement, the US
                  Borrower may borrow, repay pursuant to Section 2.06 or prepay
                  pursuant to Section 2.08 and reborrow under this Section
                  2.01(h). Funding and maintenance of Dollar Swing Line Loans
                  shall be in Dollars. Dollar Swing Line Loans shall constitute
                  "Dollar Revolving Loans" for all purposes hereunder, provided,
                  they shall be held by the Dollar Swing Line Banks (subject to
                  sub-clauses (ii) and (iii) below), and provided further, the
                  Dollar Swing Line Loans shall not be considered a utilization
                  of the Dollar Revolving Commitment for the purpose of
                  calculating the Commitment Fee only.

                           (ii) If a Dollar Swing Line Loan is outstanding more
                  than five (5) days, or at any time after a Default or an Event
                  of Default, if 100% of the Dollar Swing Line Banks so decide,
                  in their sole discretion, they may give notice to the Agent to
                  require each Bank to make a Dollar Revolving Loan in an amount
                  equal to such Bank's Commitment Percentage times the
                  outstanding principal balance of all Dollar Swing Line Loans
                  (the "Refunded Dollar Swing Line Loan") outstanding on the
                  date such notice is given; provided that the provision of this
                  subsection shall not affect the obligation of the US Borrower
                  to prepay Swing Line Loans in accordance with Section 2.01(h)
                  and 2.06(e). Upon (A) the delivery of such notice and (B) each
                  Bank either making a Dollar Revolving Loan or purchasing from
                  the Dollar Swing Line Banks a pro rata participation in such
                  Dollar Swing Line Loan as required under Section 2.01(h)(iii),
                  the Dollar Swing Line Commitments and the Dollar Revolving
                  Loan Commitments shall be terminated. Unless the Dollar
                  Revolving Commitments shall have expired or terminated, each
                  Bank shall make the proceeds of its Dollar Revolving Loan
                  available to the Agent for the pro rata account of the Dollar
                  Swing Line Banks on the next Business Day following such
                  request, in immediately available funds. The proceeds of such
                  Dollar Revolving Loans shall be immediately applied to repay
                  the Refunded Dollar Swing Line Loan.

                           (iii) At any time after a Default or an Event of
                  Default, if the Dollar Revolving Commitments shall have
                  expired or be terminated while any Dollar Swing Line Loan is
                  outstanding, the Banks, shall, notwithstanding the expiration
                  or termination of the Dollar Revolving Commitments, make a
                  Dollar Revolving Loan (which shall be deemed a "Revolving
                  Loan" for all purposes of this Agreement and the other Loan
                  Documents) and, if any Bank shall not have made its Dollar
                  Revolving Loans, such Bank shall be deemed, without further
                  action by any Person, to have purchased from the Dollar Swing
                  Line Banks a pro rata participation in such Dollar Swing Line
                  Loan in either case in an amount equal to such Bank's
                  Commitment Percentage times the outstanding principal balance
                  of such Dollar Swing Line Loan. The Agent shall notify each
                  such Bank of the amount of such Dollar Revolving Loan or
                  participation and such Bank will transfer to the Agent for




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                  the pro rata account of the Dollar Swing Line Banks on the
                  next Business Day following such notice, in immediately
                  available funds, the amount of its Dollar Revolving Loan or
                  participation.

                           (iv) If any such Bank shall not have so made its
                  Dollar Revolving Loan or its percentage participation
                  available to the Agent pursuant to this Section 2.01(h), such
                  Bank agrees to pay interest thereon for each day from such
                  date until the date such amount is paid at the lesser of (1)
                  the Federal Funds Rate on the date payment is to be made to
                  the Agent and (2) the Highest Lawful Rate. Whenever, at any
                  time after the Agent has received from any Bank such Bank's
                  Dollar Revolving Loan or participating interest in a Dollar
                  Swing Line Loan, the Agent receives any payment on account
                  thereof, the Agent will pay to such Bank its participating
                  interest in such amount (appropriately adjusted, in the case
                  of interest payments, to reflect the period of time during
                  which such Bank's participating interest was outstanding and
                  funded) which payment shall be subject to repayment by such
                  Bank if such payment received by the Agent is required to be
                  returned. Each Bank's obligation to make the Dollar Revolving
                  Loans or purchase such participating interests pursuant to
                  this Section 2.01(h) shall be absolute and unconditional and
                  shall not be affected by any circumstance, including, without
                  limitation, (A) any set-off, counterclaim, recoupment, defense
                  or other right which such Bank or any other Person may have
                  against the Dollar Swing Line Banks or either one of same, the
                  Agent or any other Person for any reason whatsoever; (B) the
                  occurrence or continuance of a Default or an Event of Default
                  or the termination of Dollar Revolving Commitments; (C) the
                  occurrence of any Material Adverse Effect; (D) any breach of
                  this Agreement by any of the Borrowers or any other Bank; or
                  (E) any other circumstance, happening or event whatsoever,
                  whether or not similar to any of the foregoing. Each Dollar
                  Swing Line Loan, once so participated by any Bank, shall cease
                  to be a Dollar Swing Line Loan with respect to that amount for
                  purposes of this Agreement, but shall continue to be a Dollar
                  Revolving Loan and be evidenced by such Bank's Dollar
                  Revolving Note.

                           (v) In the event that any Dollar Swing Line Bank
                  incurs any tax, cost or expense of the type described in
                  Sections 2.11 through 2.14, inclusive, by reason of repaying
                  or participating a Dollar Swing Line Loan as described in this
                  Section 2.01(h), the US Borrower shall reimburse such Dollar
                  Swing Line Bank the full amount of such tax, cost or expense
                  subject to the terms and conditions herein.

                           (vi) The US Borrower expressly agrees and
                  acknowledges that, in respect of each Bank's funded
                  participation interest in any Dollar Swing Line Loan, such
                  Bank shall be deemed to be in privity of contract with the US
                  Borrower and have the same rights and remedies against the US
                  Borrower under the Loan Documents as if such funded
                  participation interest in such Dollar Swing Line Loan were a
                  Dollar Revolving Loan."



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                  b. Section 2.04 - Amendment. (i) Sections 2.04(a), (b) and (c)
         are hereby deleted in their entirety and the following substituted
         therefor:

                          "(a)  Omitted

                           (b)  Omitted

                           (c)  The Dollar Revolving Loans made by each Bank
                  making a Dollar Revolving Loan shall be evidenced by a Dollar
                  Revolving Note issued to such Bank by the US Borrower (i)
                  dated the effective date of the Amendment (or such other date
                  as may be specified in Section 10.02), (ii) payable to the
                  order of such Bank and (iii) otherwise duly completed."

                  (ii) Section 2.04(d) is hereby deleted in its entirety and the
         following substituted therefor:

                        "(d) The Guilder Revolving Loans made by the Guilder
                  Revolving Loan Bank shall be evidenced by a Guilder Revolving
                  Note issued to the Guilder Revolving Loan Bank by the Parent
                  (i) dated the effective date of the Amendment (or such other
                  date as may be specified in Section 10.02), (ii) payable to
                  the order of the Guilder Revolving Loan Bank and (iii)
                  otherwise duly completed."

                  (iii) Section 2.04(e) is hereby deleted in its entirety and
         the following substituted therefor:

                        "(e) The Dollar Swing Line Loans made by each of the
                  Dollar Swing Line Banks shall be evidenced by a Dollar Swing
                  Line Note issued to such Dollar Swing Line Bank by the US
                  Borrower, (i) dated the date of the Amendment (or such other
                  date as may be specified in Section 10.02), (ii) payable to
                  the order of such Dollar Swing Line Bank and (iii) otherwise
                  duly completed."

                  c. Section 2.06 - Amendment. Section 2.06 is hereby amended by
         deleting subsections (a) and (c) thereof in their entirety.

                  d. Section 2.07 - Amendment. (i) Section 2.07 is hereby
         amended by deleting subparagraphs (a)(i) and (a)(ii) thereof and
         replacing them with the following:

                           (i) Base Rate Loans. If such Loan is a Base Rate
                  Loan, a rate per annum equal at all times to the lesser of (A)
                  the Highest Lawful Rate and (B) the sum of the Base Rate in
                  effect from time to time plus, except as set forth below, the
                  Applicable Margin in effect from time to time for Base Rate
                  Loans, and unpaid accrued interest on such Loans shall be due
                  and payable on each payment date and on the date such




                                      -6-
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                  Base Rate Loan shall be paid in full or converted; provided,
                  that with respect to all Base Rate Loans which are Dollar
                  Swing Line Loans the rate per annum as set forth in this
                  Section 2.07(a)(i) less the percentage per annum Commitment
                  Fee in effect pursuant to Section 2.10.

                  (ii) Eurocurrency Rate Loans. If such loan is a Eurocurrency
                  Rate Loan, a rate per annum equal at all times during the
                  Interest Period for such Loan to the lesser of (A) the Highest
                  Lawful Rate and (B) the sum of the Eurocurrency Rate for such
                  Interest Period plus, except as set forth below, the
                  Applicable Margin in effect as of the first day of such
                  Interest Period for Eurocurrency Rate Loans, and unpaid
                  accrued interest on such Loans shall be due and payable the
                  last day of such Interest Period; provided, in the case of an
                  Interest Period longer than three months, (i) interest shall
                  also be paid, and (ii) the Applicable Margin shall change, in
                  each case, effective as of the date occurring every three
                  months after the first day of such Interest Period, and on the
                  date such Eurocurrency Rate Loan shall be paid in full or
                  Converted.

                  (iii) Section 2.07 is hereby further amended by deleting
         subparagraph (c) thereof and replacing it with the following:

                        "(c) As used herein, "Applicable Margin" means, and
                  "Commitment Fee" means, for any day, (subject to Section
                  2.10), at such time as the Margin Ratio is in one of the
                  following ranges, the percentage per annum set forth opposite
                  such Margin Ratio:



                        Margin Ratio                     Eurocurrency        Base Rate
                                                            Margin             Margin        Commitment Fee
                                                            ------             ------        --------------
                                                                                    
         Less than 2.0 to 1.0                                  1.25%             0%              .375%
         Equal to or greater than 2.0 to 1.0                   1.50%           .25%              .375%
                  but less than 2.5 to 1.0
         Equal to or greater than 2.5 to 1.0                   1.75%           .50%              .375%


                  (iv) Section 2.07 is hereby amended by deleting subparagraph
         (d) thereof and replacing it with the following:

                       "(d) For purposes hereof, "Margin Ratio" means, as of
                  any date, the ratio of (i) the Parent's total consolidated
                  Indebtedness as of the calendar quarter ending on such date,
                  to (ii) its consolidated EBITDA for the twelve month period
                  ending on the last day of such calendar quarter.

                       The Margin Ratio set forth in the most recent Margin
                  Ratio Certificate delivered to the Administrative Agent shall,
                  for purposes of determining the Applicable Margin, be in
                  effect from the second business day after the date such Margin
                  Ratio Certificate is delivered (or is required to be
                  delivered), until the second business day after the next such
                  Margin Ratio Certificate is delivered (or is required




                                      -7-
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                  to be delivered), with the following exceptions: (a) if the
                  Administrative Agent in good faith determines that the
                  calculations of the Margin Ratio reflected in any Margin Ratio
                  Certificate are manifestly in error, the Administrative Agent
                  may correct any error and calculate the appropriate Margin
                  Ratio (and promptly give the Borrowers notice thereof with
                  supporting documentation and calculations), (b) if the Parent
                  fails to deliver any Margin Ratio Certificate when due, the
                  Margin Ratio shall be deemed to be greater than 2.5 to 1.0
                  until such Margin Ratio Certificate is delivered, and (c) in
                  the event of the consummation of any merger or acquisition of
                  a Subsidiary, the Margin Ratio shall be immediately
                  recalculated on a pro forma, trailing twelve month basis (as
                  if such Subsidiary had been acquired on the first day of such
                  twelve (12) month period) and be in effect from such
                  consummation until the earlier of (1) the second business day
                  after a new Margin Ratio Certificate is delivered or (2) the
                  consummation of another merger or acquisition of a
                  Subsidiary."

                  e.       Section 2.10 -  Amendment.  Section 2.10 is hereby
         amended by adding the following paragraph (d) thereto:

                           "(d) The Borrowers jointly and severally agree to pay
                  to the Administrative Agent, for the account of each Bank, a
                  one-time fee, in Dollars, equal to .25% of all of such Bank's
                  Commitment existing immediately after the execution of the
                  Amendment."

                  f. Section 3.02 - Amendment. Section 3.02 is hereby amended by
         modifying the reference in the last line thereof to "Refunded Guilder
         Swing Line Loan" to refer to "Refunded Dollar Swing Line Loan."

                  g. Section 4.16. Section 4.16 is hereby deleted in its
         entirety.

                  h. Section 4.19. Section 4.19 is hereby deleted in its
         entirety.

                  i. Section 4.20. A new Section 4.20 is added to read in its
         entirety as follows:

                           "Section 4.20 Year 2000. All Information Systems and
                  Equipment material to the operations of the Company or any of
                  its Subsidiaries are either Year 2000 Compliant, or any
                  reprogramming, remediation, or any other corrective action,
                  including the internal testing of all such Information Systems
                  and Equipment, will be completed by September 30, 1999.
                  Further, to the extent that such reprogramming/remediation and
                  corrective action is required, the cost thereof, as well as
                  the cost of the reasonably foreseeable consequences of failure
                  to become Year 2000 Compliant, to the Borrowers and their
                  Subsidiaries (including, without limitation, reprogramming
                  errors and the failure of other systems or equipment) will not
                  result in a Default or a Material Adverse Effect."



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                  j.       Section 5.09  -  Amendment.  Section 5.09 is hereby
         deleted and the following substituted therefor:

                           "Section 5.09 Use of Loans and Letters of Credit. All
                  Letters of Credit shall be issued for general corporate
                  purposes consistent with the terms of this Agreement and all
                  Requirements of Law. The US Borrower will use the proceeds of
                  all Dollar Revolving Loans for working capital and other
                  general corporate purposes, including for Capital Expenditures
                  and Permitted Acquisitions, consistent with the terms of this
                  Agreement and all Requirements of Law. The Parent will use the
                  proceeds of the Guilder Revolving Loans (i) for the repayment
                  of any amounts outstanding under the Guilder Swing Line Loans,
                  and (ii) for working capital and other general corporate
                  purposes consistent with the terms of this Agreement and all
                  Requirements of Law."

                  k. Section 5.10 - Amendment. Section 5.10 is hereby deleted in
         its entirety and the following is substituted therefor:

                           "Section 5.10 Additional Guarantees. (a) In the event
                  any Borrower or any of their Subsidiaries, subsequent to the
                  date of the Amendment, acquires any non-U.S. Subsidiary and
                  the cash consideration paid for such non-U.S. Subsidiary
                  exceeds the equivalent of $20,000,000.00, such non-U.S.
                  Subsidiary shall execute and deliver to the Administrative
                  Agent a Guaranty Agreement guaranteeing the Obligations on the
                  same basis as the other Guarantors. In addition, if the gross
                  revenue or total assets of such non-U.S. Subsidiary exceeds
                  five percent (5%) of the consolidated gross revenue or total
                  assets, respectively, of the Parent and its Subsidiaries, or
                  if any non-U.S. Subsidiary (other than Core Laboratories Sales
                  N.V. or Core Laboratories Australia Pty. Ltd., which shall be
                  excluded herefrom) that is not a Credit Party changes in such
                  a manner that said Subsidiary: (i) has total gross revenue or
                  total assets constituting five percent (5%) or more of the
                  consolidated total gross revenue or total assets of the Parent
                  and all of its Subsidiaries, such Subsidiary upon the written
                  request of the Majority Banks shall execute and deliver to the
                  Administrative Agent a Guaranty Agreement guaranteeing the
                  Obligations on the same basis as the other Guarantors. Except
                  as otherwise expressly provided herein, all domestic
                  Subsidiaries shall be Guarantors hereunder at all times."

                           "(b) If any Subsidiary guarantees the Indebtedness,
                  or any part thereof, permitted under Section 6.01(g), such
                  Subsidiary shall immediately, if it has not already done so,
                  execute and deliver to the Administrative Agent a Guaranty
                  Agreement guaranteeing the Obligations on the same basis as
                  the other Guarantors."

                  l. Section 5.11- Amendment. Section 5.11 is hereby deleted in
         its entirety and the following is substituted therefor:



                                      -9-
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                           "Section 5.11 Further Assurances in General. Each
                  Borrower at its expense shall, and shall cause each of its
                  Subsidiaries to, promptly execute and deliver all such other
                  and further documents, agreements and instruments in
                  compliance with or accomplishment of the covenants and
                  agreements of a Borrower or any of its Subsidiaries in the
                  Loan Documents, including, without limitation, the
                  accomplishment of any condition precedent that may have been
                  waived by the Banks prior to the initial Borrowing or Letter
                  of Credit or any subsequent Borrowings or Letters of Credit."

                  m.       Section 5.13. A new Section 5.13 is added to read in
         its entirety as follows:

                           "Section 5.13 Year 2000. Each Borrower will ensure
                  that its Information Systems and Equipment are at all times
                  after September 30, 1999, Year 2000 Compliant, except insofar
                  as the failure to do so could not reasonably be expected to
                  result in a Material Adverse Affect, and shall notify the
                  Administrative Agent and all Banks promptly upon detecting any
                  failure of the Information Systems and Equipment to be Year
                  2000 Compliant if same could reasonably be expected to result
                  in a Material Adverse Effect. In addition, the Borrowers shall
                  provide the Administrative Agent and all Banks with such
                  information about its year 2000 computer readiness (including,
                  without limitation, information as to contingency plans,
                  budgets and testing results) as the Administrative Agent or
                  such Banks shall reasonably request."

                  n. (i) Section 6.01(d) - Amendment. Section 6.01(d) is hereby
         deleted in its entirety and the following substituted therefor:

                           "(d) subject to the limitations of Section 6.07,
                  unsecured Indebtedness owing to a Borrower by any of its
                  Subsidiaries or owing by a Borrower to any of its
                  Subsidiaries; provided, any such Indebtedness in excess of
                  $10,000,000 shall be evidenced by a subordinated promissory
                  note in a form reasonably satisfactory to the Administrative
                  Agent."

                  (ii)     A new subsection 6.01(g) is hereby added to read as
         follows:

                           "(g) Indebtedness of the U.S. Borrowers evidenced by
                  8.11% Guaranteed Senior Notes, Series A, Due 2009 in an
                  original principal amount of $35,000,000 and 8.21% Guaranteed
                  Senior Notes, Series B, Due 2011 in an original principal
                  amount of $40,000,000 and guaranties of said Indebtedness by
                  the Guarantors."

                  o.       Section  6.03 -  Amendment. Section 6.03 is hereby
         deleted in its entirety and the following substituted therefor:



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                           "Section 6.03 Derivatives. The Borrowers shall not,
                  and shall not permit any of their Subsidiaries to, enter into
                  any Derivatives other than interest rate and foreign exchange
                  Derivatives entered into for purposes of hedging bona fide
                  interest and foreign exchange risk and not for speculation.
                  Any Derivative Agreements entered into with any of the Banks
                  shall be considered Loan Documents and any Borrowers'
                  Obligations therewith shall be guaranteed by the Guaranties."

                  p.       Section 6.04 - Amendment. (i) Section 6.04(a) is
         hereby deleted in its entirety and the following substituted therefor:

                           "(a) Fixed Charge Coverage Ratio. As of the last day
                  of any month, the Parent will not permit the ratio of (i) its
                  consolidated EBITDA for the twelve (12) month period then
                  ended calculated on a rolling twelve (12) month basis to (ii)
                  its consolidated Fixed Charges for such twelve month period to
                  be less than 1.4 to 1.0 during the term hereof. In calculating
                  the Fixed Charge Coverage Ratio subsequent to the date of the
                  Amendment, for any acquisition accounted for on a pooling
                  basis the historical EBITDA and Fixed Charges of the acquired
                  company, for the preceding twelve (12) months (or other
                  relevant calculation period) as shown by said acquired
                  company's most recent audited financial statements (when
                  available) and subsequent unaudited interim statements, shall
                  be included as of the date of such acquisition (or next month
                  or quarter-ending period)."

                  (ii) Section 6.04(b) is hereby deleted in its entirety and the
         following is substituted therefor:

                           "(b) Indebtedness-to-EBITDA Ratio. As of any date of
                  determination, the Parent will not permit the ratio of (i) its
                  total consolidated Indebtedness as of the last day of the
                  fiscal quarter immediately preceding the date of determination
                  to (ii) its consolidated EBITDA for the twelve month period
                  ending on the last day of the quarter immediately preceding
                  the date of determination, calculated on a rolling twelve (12)
                  month basis, to be greater than (A) 3.0 to 1.0 from the date
                  of the Amendment through June 30, 2001, (B) 2.5 to 1.0 from
                  July 1, 2001 through June 30, 2003, and (C) 2.0 to 1.0 from
                  July 1, 2003 through the Termination Date. In calculating the
                  Indebtedness to EBITDA Ratio subsequent to the date of the
                  Amendment, the historical EBITDA of the acquired company for
                  the preceding twelve (12) months (or other relevant
                  calculation period) as shown by said acquired company's most
                  recent audited financial statements (when available) and
                  subsequent unaudited interim statements, shall be included, on
                  a pro forma basis, as of the date of such acquisition (or next
                  month or quarter-ending period)."

                  (iii) Section 6.04(c) is hereby deleted in its entirety and
         the following is substituted therefor:



                                      -11-
   12
                           "(c) Minimum Net Worth. The Parent will not permit
                  consolidated Net Worth to at any time be less than the sum of
                  (i) $145,000,000.00 plus (ii) fifty percent (50%) of Net
                  Income for any fiscal quarter ending after the date of the
                  Amendment (excluding any such fiscal quarter in which Net
                  Income is a negative number), plus (iii) 75% of the net
                  proceeds or the net increase resulting from any issuance of
                  any stock of the Parent or any sale or issuance of any stock
                  of any Subsidiary (if such sale or issuance is otherwise
                  permitted herein) after the date of the Amendment."

                  q.       Section 6.07 - Amendment. (i) Section 6.07(f) is
         hereby deleted in its entirety and the following is substituted
         therefor:

                           "(f) Capital Expenditures (including Capital Leases,
                  but excluding Capital Expenditures through the date of
                  acquisition of any Person accounted for as a pooling of
                  interests) of not more than (i) $12,500,000 during the
                  remainder of calendar year 1999; (ii) $25,000,000 for calendar
                  year 1999 and (iii) increasing by 10% per annum for each
                  calendar year subsequent to 1999 during the term hereof;"

                  (ii)     Section 6.07 is hereby amended by deleting paragraph
         (g) thereof and replacing it with the following:

                           "(g) acquisitions (each, a "Permitted Acquisition")
                  by the Parent or any of its Subsidiaries of capital stock or
                  other equity interests in any other Person the consideration
                  for which is: (i) common stock of the Parent or (ii) cash of
                  not more than $20,000,000.00 in any single acquisition,
                  including assumption of debt during the term hereof; provided
                  that (1) the total consideration paid for any such individual
                  acquisition not exceed $50,000,000.00, (2) the Borrowers
                  remain in compliance with all financial covenants set forth in
                  the Loan Documents on a pro forma basis, (3) no Default exists
                  or would occur as a result of such acquisition, and (4) the
                  Person that is the subject of the acquisition operates a
                  business that is the same as or substantially similar to the
                  Business of the Parent or an existing Subsidiary;"

                  r.       Section 6.11 - Prepayment of Indebtedness.  A new
         Section 6.11 is hereby added to read as follows:

                           "Section 6.11 Payment of Indebtedness. None of the
                  Borrowers nor any of their Subsidiaries will prepay any
                  Indebtedness permitted under Section 6.01(g) hereof (except in
                  accordance with regularly scheduled payments required by the
                  terms thereof) nor will they establish any sinking fund for
                  such purpose or in any other manner defease or beneficially
                  prepay such Indebtedness provided, said parties may prepay
                  such Indebtedness, notwithstanding the restrictions otherwise
                  imposed in Section 6.07, if: (i), such prepayment is completed
                  at a discount to the face value of the Indebtedness so prepaid
                  as of the date of such prepayment, (ii) simultaneously




                                      -12-
   13

                  therewith, said prepaying party prepays a pro rata amount (as
                  determined by the Administrative Agent in its sole discretion)
                  of the Obligations owing in respect of the Revolving Loans and
                  (iii) no Default or Event of Default has occurred hereunder
                  and is continuing."

                  s.       Section 10.18. A new Section 10.18 is hereby added
         to the Credit Agreement to read as follows:

                           "Section 10.18 Euro. (i) If, at any time
                  that a Guilder Revolving Loan is outstanding, Dutch Guilders
                  are fully replaced as the lawful currency of the Netherlands
                  by the Euro so that all payments are to be made in the
                  Netherlands in Euros and not in Dutch Guilders, then each such
                  Guilder Revolving Loan shall be automatically converted into a
                  Loan denominated in Euros in a principal amount equal to the
                  amount of Euros into which the principal amount of such
                  Guilder Revolving Loan would be converted pursuant to the EMU
                  Legislation and thereafter no further Loans will be available
                  in Dutch Guilders but Loans in Euros shall be thereafter
                  available in the same maximum aggregate equivalent in Dollars
                  as was applicable to Guilder Revolving Loans with the basis of
                  accrual of interest, notice requirements and payment offices
                  with respect to such converted Loans to be consistent with the
                  convention and practices in the London interbank market for
                  Euro denominated Loans at the time of conversion as reasonably
                  determined by the Administrative Agent."

                  t.       Section  10.19.  A new Section 10.19 is hereby added
         to the Credit Agreement to read as follows:

                           "Section 10.19 Pro Rata Treatment. Notwithstanding
                  any other provisions contained herein, all parties hereto
                  recognize that the Loans are held by the Banks in varying
                  percentages and that not each member of the Bank Group
                  participates in each Loan. Accordingly, when the term "pro
                  rata" is used in regard to making payments by the Borrowers or
                  distributing payments by the Administrative Agent, it shall
                  mean that each Bank receives its share of such payment pro
                  rata within each Loan in which it participates."

                  u.       Release of Pledge Agreements. Each Agent and Bank
         hereby authorizes and directs the Administrative Agent to release, and
         hereby releases, all property which is Collateral for the Obligations
         of the Credit Parties under the Credit Agreement and the other Loan
         Documents. The Administrative Agent, on behalf of the Bank Group hereby
         terminates in their entirety each of the Pledge Agreements, reassigns
         and releases all of the shares pledged thereunder, and agrees that,
         from the date of this Agreement, the Pledge Agreements shall be of no
         further force or effect, provided such release shall not invalidate or
         in any way affect, the Guaranty Agreements or any Person's liabilities
         or obligations under the Guaranty Agreements. The Administrative Agent
         agrees to execute such other documents and take any




                                      -13-
   14

         such steps as any of the Borrowers may reasonably request to effect the
         terns of this Section, all at the expense of the requesting Borrower.

                  v. (a) The Commitments of each of the Banks shown on the
         signature pages of the Credit Agreement are hereby deleted and replaced
         with the new amounts shown on the signature pages to this Amendment.

                  (b) The exhibits attached to this Amendment supersede and
         replace the comparable, marked Exhibits to the Credit Agreement.

                  (c) All references to Tranche A Loans, Tranche B Loans,
         Guilder Swing Line Loans, Collateral, Pledge Agreements, Security
         Documents and related items are generally modified and/or deleted, as
         appropriate, to comport with the intent of the parties as expressed
         herein.

                  (d) All references to the Borrowers shall no longer include
         the UK Borrower and references to the UK Borrower shall instead be to a
         Guarantor or a Credit Party, as the context requires to comport with
         the intent of the parties as expressed herein.

                  (e) The certificates required by Section 5.01(a)(ii) and
         5.01(c) shall be combined into the form attached hereto as
         Exhibit 5.01.

                  w.  Annex A - Amendment.

                      (i)           The following definitions are hereby added
                  to the Annex of definitions to read as follows:

                                    A. "Amendment" shall mean that certain
                           Amendment to Amended and Restated Credit Agreement,
                           dated July ____, 1999, by and among the Borrowers,
                           the Guarantors, the Banks and the Agents, which
                           Amendment, among other things, amended certain
                           provisions of this Agreement."

                                    B. "Dollar Swing Line Commitment" means the
                           obligation of the Dollar Swing Line Banks to make the
                           Dollar Swing Line Loans pursuant to Section 2.01(h),
                           and is part of the "Dollar Revolving Commitment."

                                    C. "Dollar Swing Line Loan" has the meaning
                           specified  in Section 2.01(h).

                                    D. "Dollar Swing Line Note" means a
                           promissory note of the US Borrower payable to the
                           order of a Dollar Swing Line Bank substantially in
                           the form of Exhibit 2.04(e) evidencing the aggregate
                           indebtedness of the US




                                      -14-
   15

                           Borrower to such Dollar Swing Line Bank resulting
                           from the Dollar Swing Line Loans made by such Dollar
                           Swing Line Bank together with all modifications,
                           extensions, renewals, and rearrangements thereof from
                           time to time in effect.

                                    E. "Dollar Swing Line Banks" means Bankers
                           Trust Company and any other Banks so designated as
                           Dollar Swing Line Banks from time to time hereunder.

                                    F. "EMU Legislation" shall mean the
                           legislative measures of the European Council for the
                           introduction of, changeover to or operation of a
                           single or unified European currency."

                                    G. "Euro" shall mean the European Monetary
                           Unit issued pursuant to the terms of the EMU
                           Legislation."

                                    H. "Guilder Revolving Loan Bank" means
                           Bankers Trust Company, its successors and assigns.

                                    I. "Information Systems and Equipment" means
                           all material computer hardware and software, as well
                           as other information processing systems, or any
                           equipment containing embedded microchips, whether
                           directly owned, licensed, leased, operated or
                           otherwise controlled by the Borrowers or any of their
                           Subsidiaries, including through third-party service
                           providers, and which, in whole or in part, are
                           integral to, the Borrowers' or any of their
                           Subsidiaries' conduct of their business."

                                    J. "Permitted Acquisition" has the meaning
                           specified in Section 6.07(g)."

                                    K. "Refunded Dollar Swing Line Loan" has the
                           meaning specified in Section 2.01(h)."

                                    L. "Year 2000 Compliant" means that all
                           Information Systems and Equipment accurately process
                           date data (including, but not limited to,
                           calculating, comparing and sequencing), before,
                           during and after the year 2000, as well as same and
                           multi-century dates, or between the years 1999 and
                           2000, taking into account all leap years, including
                           the fact that the year 2000 is a leap year, and
                           further, that when used in combination with, or
                           interfacing with, other Information Systems and
                           Equipment, shall accurately accept, release and
                           exchange date data, and shall in all material
                           respects continue to function in the same manner as
                           it performs today and shall not otherwise impair the
                           accuracy or functionality of Information Systems and
                           Equipment."



                                      -15-
   16

                           (ii) The hereinafter listed definitions are hereby
                    deleted from the Annex of definitions and the following
                    substituted therefor:

                                    A. "Applicable Margin" has the meaning
                           specified in Section 2.07(c)."

                                    B. "Base Rate Loan" means a Dollar Revolving
                           Loan that the applicable Borrower has designated, or
                           is deemed to have designated, as such in accordance
                           with Article II and shall include all Dollar Swing
                           Line Loans, all as shown on the signature page of
                           such Bank to the Amendment."

                                    C. "Borrowing" means a Revolving Borrowing."

                                    D. "Commitment" means as to any Bank, the
                           sum of such Bank's Dollar Revolving Commitment,
                           Guilder Revolving Commitment and, in the case of the
                           Dollar Swing Line Banks, the Dollar Swing Line
                           Commitment."

                                    E. "Dollar Revolving Commitment" means the
                           amount set forth under the caption "Dollar Revolving
                           Commitment" for each Bank on the signature pages to
                           the Amendment, as such amount may be increased
                           pursuant to this Agreement."

                                    F. "Dollar Revolving Loan" means a Revolving
                           Loan to the US Borrower made in US Dollars pursuant
                           to Section 2.01(c)."

                                    G. "EBITDA" means for any period, (a) the
                           sum of the following: (i) the Net Income for such
                           period, (ii) the amount of amortization or write-off
                           of deferred financing costs which were deducted from
                           gross income in determining such Net Income for such
                           period, (iii) the amount of depreciation and
                           amortization expense which was deducted from gross
                           income in determining such Net Income for such
                           period, (iv) the amount of Interest Expense which was
                           deducted in the calculation of such Net Income for
                           such period, (v) the amount of income taxes deducted
                           in the calculation of such Net Income for such
                           period, and (vi) any writedowns of assets or similar
                           non-recurring, non cash items deducted in the
                           calculation of Net Income for such period less, (b)
                           (1) any interest income included in the calculation
                           of Net Income for such period, (2) the amount of
                           gains on sales of assets (excluding sales in the
                           ordinary course of business) and other extraordinary
                           gains which were added in the calculation of such Net
                           Income for such period, and (3) other cash flow of
                           non-Credit Parties that is not available to any of
                           the Borrowers due to currency controls, limits on
                           dividend or profit repatriations, local tax
                           requirements or similar laws or regulations, all as
                           determined on a consolidated basis in accordance with
                           GAAP.



                                      -16-
   17

                                    H. "Eurocurrency Rate" means, with respect
                           to each Interest Period for each Eurocurrency Rate
                           Loan, the quotient of (a) (i) the composite offered
                           rate for London interbank deposits (rounded to the
                           nearest 1/16 of 1%) for deposits of US dollars, Dutch
                           Guilders or Euros, as applicable, for a period
                           equivalent to the Interest Period to be applicable to
                           such Eurocurrency Rate Loan, determined as of 11:00
                           a.m. (London time) on the date which is two (2)
                           Business Days prior to the commencement of such
                           Interest Period in the case of a Eurodollar Rate Loan
                           denominated in Dollars and three (3) Business Days
                           prior to the commencement of such Interest Period in
                           the case of a Eurocurrency Rate Loan denominated in a
                           Foreign Currency, and which, at the sole option of
                           the Administrative Agent, may be the rate which is
                           displayed on Telerate page 3750 (British Bankers'
                           Association Interest Settlement Rates) or such other
                           page as may replace such page 3750 or otherwise be
                           applicable on such system; or (ii) if the rate in
                           clause (i) is not so displayed on such date, or the
                           Administrative Agent chooses not to use such screen
                           shall be the arithmetic average (rounded to the
                           nearest 1/16 of 1%) of the offered quotation to
                           first-class banks in the interbank Eurocurrency
                           market by the Administrative Agent for deposits of
                           Dollars, Dutch Guilders or Euros, as applicable, of
                           an amount in same day funds comparable to the
                           outstanding principal amount of the Eurocurrency Rate
                           Loan of the Administrative Agent (in its capacity as
                           a Bank) for which an interest rate is then being
                           determined with maturities comparable to the Interest
                           Period to be applicable to such Eurocurrency Rate
                           Loan, determined as of 10:00 a.m. (New York time) on
                           the date which is two Business Days in the case of
                           Eurocurrency Rate Loans denominated in Dollars and
                           three (3) Business Days in the case of Eurocurrency
                           Rate Loans denominated in a Foreign Currency prior to
                           the commencement of such Interest Period, divided
                           (and rounded upward to the next whole multiple of
                           1/16 of 1%) by (b) a percentage equal to 100% minus
                           the then stated maximum rate of all reserve
                           requirements (including without limitation, any
                           marginal, emergency, supplemental, special or other
                           reserves) applicable to any member bank of the
                           Federal Reserve System in respect of "Eurocurrency
                           liabilities" as defined in Regulation D of the Board
                           of Governors of the Federal Reserve System (or any
                           successor category of liabilities under Regulation
                           D)."

                                    I. "Guilder Revolving Commitment" means the
                           amount set forth on the signature page of the Guilder
                           Revolving Loan Bank to the Amendment, as amended from
                           time to time.

                                    J. "Loan Documents" means this Agreement,
                           the Notes, the Letters of Credit, the Guaranty
                           Agreements and all other agreements, instruments and
                           documents, including, without limitation, notes,
                           warrants, guaranties, subordination agreements,
                           powers of attorney, consents, the



                                      -17-
   18

                           Subordination Agreement, letter agreements,
                           contracts, notices, leases, amendment, Letter of
                           Credit applications and reimbursement agreements, any
                           documents executed by any of the Borrowers with any
                           of the Banks evidencing any obligations in respect of
                           any Derivative, and all other writings heretofore,
                           now, or hereafter executed by or on behalf of a
                           Borrower or any of its Subsidiaries, any of their
                           respective Affiliates or any other Person in
                           connection with or relating to this Agreement,
                           together with all agreements, instruments and
                           documents referred to therein or contemplated
                           thereby."

                                    K. "Notes" means the Revolving Notes."

                                    L. "Revolving Borrowing" means a group of
                           Revolving Loans of a single Type made by the Banks,
                           or Converted into such, as applicable, on a single
                           date and may be a Dollar Revolving Loan, a Dollar
                           Swing Line Loan or a Guilder Revolving Loan and, in
                           the case of a Revolving Loan that is also a
                           Eurocurrency Rate Loan, as to which a single Interest
                           Period is in effect."

                                    M. "Revolving Loan" means Dollar Revolving
                           Loans, Dollar Swing Line Loans and Guilder Revolving
                           Loans."

                                    N. "Revolving Notes" means Dollar Revolving
                           Notes, Dollar Swing Line Notes and Guilder Revolving
                           Notes."

                                    O. "Termination Date" means June 30, 2004 or
                           , in the case of the Revolving Commitments, such
                           earlier date on which the Revolving Commitments are
                           terminated pursuant to Section 2.05 or Section 7.01."

                                    P. "Total Dollar Revolving Commitment"
                           means, as of any date, an amount equal to the sum of
                           the Banks' Dollar Revolving Commitments as of such
                           date (inclusive of the Dollar Swing Line
                           Commitments), which shall never exceed $95,000,000.00
                           in the aggregate."

                  2.       Waiver of Violations of Section 5.10. Any violation
of the terms of Section 5.10 prior to the date of this Amendment is hereby
waived through the date of this Amendment but not otherwise.

                  3.       Representations and Warranties. Each Borrower and
Guarantor hereby represents and warrants to the Administrative Agent and Banks
that (a) this Amendment has been duly executed and delivered on behalf of each,
(b) this Amendment constitutes a valid and legally binding agreement enforceable
against each in accordance with its terms, except as such enforceability may be
limited by bankruptcy, insolvency, reorganization, moratorium, fraudulent
transfer or other similar laws relating to or affecting the enforcement of
creditors' rights generally, and by general principles of equity regardless of
whether such enforceability is a proceeding in equity




                                      -18-
   19

or at law, (c) the representations and warranties contained in the Credit
Agreement as modified hereby are true and correct on and as of the date hereof
as though made as of the date hereof except as heretofore otherwise disclosed in
writing to the Administrative Agent (other than those of such representations
and warranties which by their express terms speak to a date on or before the
date hereof), (d) no Default or Event of Default exists under the Credit
Agreement or any of the Loan Documents as modified hereby, and (e) the
execution, delivery and performance of this Amendment has been duly authorized
by all Borrowers and Guarantors, by all appropriate corporate action and does
not violate any of their respective charters or bylaws. Said parties will
provide evidence to the Administrative Agent of the items contained in
sub-sections (a) and (e) of this Section 3.

                  4. Reference to the Credit Agreement and Effect on the Notes
and Other Documents executed pursuant to the Credit Agreement.

                  (a) Upon the effectiveness of this Amendment, each reference
in the Credit Agreement to "this Agreement," "hereunder," "herein," "hereof" or
words of similar import shall mean and be a reference to the Credit Agreement,
as amended hereby.

                  (b) Upon the effectiveness of this Amendment, each reference
in the Notes, the Security Documents and the other Loan Documents delivered or
to be delivered pursuant to the Credit Agreement shall mean and be a reference
to the Credit Agreement as amended hereby.

                  5. Ratification of Credit Agreement and Other Loan Documents
and Release.

                  (a) Each party hereto hereby confirms and ratifies the Credit
Agreement and each of the other Loan Documents as amended hereby and
acknowledges and agrees that the same shall continue in full force and effect as
amended hereby. Each Guarantor hereby reaffirms its Guaranty and agrees that
such is still in effect, in regard to the Credit Agreement and the Obligations,
as amended hereby. The Parent specifically affirms that its Guaranty is in
effect in regard to the full amount of Dollar Revolving Loans, notwithstanding
the cancellation of the Tranche A and Tranche B Loans, and that it is
unconditionally, jointly and severally liable for the repayment thereof. Each of
the undersigned parties not previously a party to the Credit Agreement expressly
assumes all duties, Obligations and liabilities of a Guarantor under the Credit
Agreement as if it had executed a Guaranty Agreement and, by its execution
hereof, hereby acknowledges said duties, Obligations and liabilities.

                  (b) The Administrative Agent and each of the Banks hereby
releases any of the Guarantors under the Credit Agreement who are not
signatories to this Amendment from any liability under its Guaranty.

                  6. Headings. Section headings in this Amendment are included
herein for convenience of reference only and shall not constitute a part of this
Amendment for any other purpose.



                                      -19-
   20
                  7. Release. Each of the Borrowers and each of the Guarantors
does hereby release and forever discharge the Administrative Agent and each of
the Banks and each affiliate thereof and each of their respective employees,
officers, directors, trustees, agents, attorneys, successors, assigns or other
representatives from any and all claims, demands, damages, actions,
cross-actions, causes of action, costs and expenses (including legal expenses),
of any kind or nature whatsoever, whether based on law or equity, which any of
said parties has held or may now or in the future own or hold, whether known or
unknown, for or because of any matter or thing done, omitted or suffered to be
done on or before the actual date upon which this Amendment is signed by any of
such parties (a) arising directly or indirectly out of the Loan Documents, or
any other documents, instruments or any other transactions relating thereto
and/or (b) relating directly or indirectly to all transactions by and between
the Borrowers, their Subsidiaries, or their representatives and the
Administrative Agent and each Bank or any of their respective directors,
officers, agents, employees, attorneys or other representatives. Such release,
waiver, acquittal and discharge shall and does include, without limitation, any
claims of usury, fraud, duress, misrepresentation, lender liability, control,
exercise of remedies and all similar items and claims, which may, or could be,
asserted by any of the Borrowers or the Guarantors.

                  8. Counterparts. This Amendment may be signed in any number of
counterparts, and delivered in facsimile or in original document form, each of
which shall be construed as an original, but all of which together shall
constitute one and the same instrument.

                  9. Conditions to Effectiveness. This Amendment shall become
effective immediately upon (a) the execution and delivery to the Administrative
Agent of: (i) signed originals hereof by all parties, (ii) Guaranty Agreements
from all Subsidiaries becoming Guarantors pursuant to Section 5.10, (iii)
executed Notes in favor of any new Banks and other Banks, as required,
evidencing the indebtedness described in the Credit Agreement (including,
without limitation, Dollar Swing Line Notes), and (iv) an opinion from: (Y)
Vinson & Elkins LLP and (Z) John Denson, general counsel to the Credit Parties,
in respect hereof reasonably satisfactory to the Administrative Agent; and (b)
payment by the Borrowers of (i) the fee referenced in Section 2.10, above, (ii)
all amounts outstanding under the Tranche A Loan, the Tranche B Loan and the
Guilder Swing Line Loan and (iii) all fees, costs and expenses due and owing to
the Administrative Agent or any of the Banks, as provided herein, provided, this
Amendment shall not become effective unless the representations and warranties
contained in Section 3 of this Amendment shall be true and correct in all
material respects.

                  10. GOVERNING LAW. THIS AMENDMENT (INCLUDING THE VALIDITY AND
ENFORCEABILITY HEREOF) SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH,
THE LAWS OF THE STATE OF NEW YORK.

                  11. FINAL AGREEMENT OF THE PARTIES. THIS AMENDMENT AND THE
OTHER LOAN DOCUMENTS REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY
NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,





                                      -20-
   21

CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO ORAL
AGREEMENTS BETWEEN THE PARTIES.


                            [Signature Pages Follow]




                                      -21-
   22
                 IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be executed by their respective officers thereunto duly authorized
as of the date first above written.


BORROWERS:

                                    CORE LABORATORIES N.V.

                                    BY:     CORE LABORATORIES INTERNATIONAL
                                            B.V., ITS SOLE MANAGING DIRECTOR



                                    By:     /s/ Jacobus Schouten
                                       -----------------------------------------
                                    Name:   Jacobus Schouten
                                    Title:  Managing Director


                                    CORE  LABORATORIES, INC.



                                    By:     /s/ Richard L. Bergmark
                                       -----------------------------------------
                                            Richard L. Bergmark
                                            Executive Vice President





   23
                               GUARANTORS:

                               CORE LABORATORIES N.V. BY: CORE LABORATORIES
                               INTERNATIONAL B.V., ITS SOLE MANAGING DIRECTOR



                               By:        /s/ Jacobus Schouten
                                  ----------------------------------------
                               Name:      Jacobus Schousten
                               Title:     Managing Director


                               CORE LABORATORIES, INC.



                               By:        /s/ Richard L. Bergmark
                                  ----------------------------------------
                                          Richard L. Bergmark
                                          Executive Vice President


                               SAYBOLT INTERNATIONAL B.V.



                               By:        /s/ Jan Heinsbroek
                                  ----------------------------------------
                               Name:      Jan Heinsbroek
                               Title:     Managing Director


                               SAYBOLT INC.
                               SAYBOLT NORTH AMERICA, INC.



                               By:        /a/ Monty L. Davis
                                  ----------------------------------------
                               Name:      Monty L. Davis
                               Title:     President


                               SAYBOLT NEDERLAND B.V.



                               By:        /s/ Jan Heinsbroek
                                  ----------------------------------------
                               Name:      Jan Heinsbroek
                               Title:     Managing Director


                               OWEN OIL TOOLS, INC.



                               By:        /s/ David S. Wesson
                                  ----------------------------------------
                               Name:      David S. Wesson
                               Title:     President


                               THE ANDREWS GROUP INTERNATIONAL, INC.



                               By:        /s/ Robert Andrews
                                  ----------------------------------------
                               Name:      Robert Andrews
                               Title:     President & CEO


                               AGI MEXICANA, DE S.A.



                               By:        /s/ R. L. Bergmark
                                  ----------------------------------------
                               Name:      R. L. Bergmark
                               Title:     Authorized Representative




   24



                                                 BANKS:

Tranche A Commitment: Terminated                 BANKERS TRUST COMPANY
Tranche B Commitment: Terminated
Dollar Revolving Commitment: $13,500,000
Guilder Revolving Commitment:
          $5,000,000 Equivalent                  By: /s/ Marcus M. Tarkington
Guilder Swing Line                                  --------------------------
Commitment: Terminated                           Name: Marcus M. Tarkington
Dollar Swing Line Commitment: $10,000,000.00     Title: Director


                                                 Address:

                                                 130 Liberty Street, 14th Floor
                                                 New York, New York 10006
                                                 Telecopy No.: (212) 250-6029

                                                 Domestic Lending Office:

                                                 Bankers Trust
                                                 130 Liberty Street, 14th Floor
                                                 New York, New York 10006

                                                 Eurocurrency Lending Office:

                                                 Bankers Trust
                                                 130 Liberty Street, 14th Floor
                                                 New York, New York 10006

                                                 ADMINISTRATIVE AGENT:

                                                 BANKERS TRUST COMPANY



                                                 By: /s/ Marcus M. Tarkington
                                                    --------------------------
                                                 Name: Marcus M. Tarkington
                                                 Title: Director


   25



Tranche A Commitment: Terminated              BANK OF AMERICA, N.A., FORMERLY
Tranche B Commitment: Terminated              KNOWN AS NATIONSBANK, N.A.
Dollar Revolving Commitment: $18,500,000.00
Guilder Revolving Commitment:
        0 Equivalent
Guilder Swing Line                            By: /s/ Patrick M. Delaney
Commitment: Terminated                           ----------------------------
                                                 Patrick M. Delaney
                                                 Managing Director

                                              Address:

                                              700 Louisiana, 8th Floor
                                              Houston, Texas 77002
                                              Telecopy No.: (713) 247-6568

                                              Domestic Lending Office:

                                              Bank of America, N.A.
                                              Attn:    Paul Colon
                                              901 Main Street
                                              Dallas, Texas 75202
                                              Telecopy No.: (713) 651-4834

                                              Eurocurrency Lending Office:

                                              Bank of America, N.A.
                                              Attn:    Paul Colon
                                              901 Main Street
                                              Dallas, Texas 75202
                                              Telecopy No.: (713) 651-4834

                                              SYNDICATION AGENT:

                                              BANK OF AMERICA SECURITIES LLC.,
                                              as Syndication Agent and as
                                              Issuing Bank



                                              By: /s/ Jeff Susman
                                                 ----------------------------
                                                    Jeff Susman
                                                    Principal



   26

Tranche A Commitment:  Terminated             CIBC INC.
Tranche B Commitment: Terminated
Dollar Revolving Commitment: $18,000,000.00
Guilder Revolving Commitment:
       0 Equivalent
                                              By: /s/ Roger Colden
                                                  ----------------------------
                                              Name: Roger Colden
                                              Title: Authorized Signatory


                                              Address:

                                              1600 Smith Street
                                              Houston, Texas  77002
                                              Telecopy No.:  (713) 650-7675

                                              Domestic Lending Office:

                                              2 Paces West
                                              2727 Paces Ferry Road, Suite 1200
                                              Atlanta, Georgia 30339

                                              Eurocurrency Lending Office:

                                              2 Paces West
                                              2727 Paces Ferry Road, Suite 1200
                                              Atlanta, Georgia 30339


   27



Tranche A Commitment:  Terminated              BANK ONE, LOUISIANA, N.A., AS
Tranche B Commitment: Terminated               SUCCESSOR TO FIRST NATIONAL BANK
Dollar Revolving Commitment: $15,000,000.00    OF COMMERCE
Guilder Revolving Commitment:
          0 Equivalent

                                               By: /s/ J. Charles Freel, Jr.
                                                  -----------------------------
                                               Name: J. Charles Freel, Jr.
                                               Title: Senior Vice President

                                               Address:

                                               201 St. Charles Ave., 29th Floor
                                               New Orleans, Louisiana  70170
                                               Telecopy No.: (504) 623-6555


                                               Domestic Lending Office:
                                               201 St. Charles Ave., 29th Floor
                                               New Orleans, Louisiana  70170
                                               Telecopy No.: (504) 623-6555

                                               Eurocurrency Lending Office:

                                               201 St. Charles Ave., 29th Floor
                                               New Orleans, Louisiana  70170
                                               Telecopy No.: (504) 623-6555





   28

Tranche A Commitment:  Terminated           BANQUE NATIONALE DE PARIS
Tranche B Commitment: Terminated
Dollar Revolving Commitment:                $10,000,000.00
Guilder Revolving Commitment:
          0 Equivalent
                                            By: /s/ Warren Ross
                                               ---------------------------------
                                            Name: Warren Ross
                                            Title: Assistant Vice President

                                            Address:

                                            333 Clay Street, Suite 3400
                                            Houston, Texas 77002
                                            Telecopy No.: (713) 659-1414

                                            Domestic Lending Office:

                                            333 Clay Street, Suite 3400
                                            Houston, Texas 77002
                                            Telecopy No.: (713) 659-1414

                                            Eurocurrency Lending Office:

                                            333 Clay Street, Suite 3400
                                            Houston, Texas 77002
                                            Telecopy No.: (713) 659-1414


   29

Tranche A Commitment:  Terminated              ABN AMRO BANK, N.V.
Tranche B Commitment: Terminated
Dollar Revolving Commitment: $15,000,000.00
Guilder Revolving Commitment:
          0 Equivalent
                                               By: /s/ Brandi Lippincott
                                                  ------------------------------
                                               Name: Brandi Lippincott
                                               Title: Assistant Vice President



                                               By: /s/ Stuart Murray
                                                  ------------------------------
                                               Name: Stuart Murray
                                               Title: Vice President


                                               Address:

                                               Three Riverway, Suite 1700
                                               Houston, Texas 77056
                                               Telecopy No.: (713) 621-5801

                                               Domestic Lending Office:

                                               208 South LaSalle, Suite 1500
                                               Chicago, Illinois 60604-1003
                                               Attn:  Loan Administration
                                               Telecopy No.:  (312) 992-5157
                                               Phone No.: (312) 992-5152

                                               Eurocurrency Lending Office:

                                               208 South LaSalle, Suite 1500
                                               Chicago, Illinois 60604-1003
                                               Attn:  Loan Administration
                                               Telecopy No.:  (312) 992-5157
                                               Phone No.: (312) 992-5152


   30



Tranche A Commitment:  Terminated            COMERICA BANK
Tranche B Commitment: Terminated
Dollar Revolving Commitment: $5,000,000.00
Guilder Revolving Commitment:
          0 Equivalent
                                             By: /s/ Brian J. Walsh
                                                 ------------------------------
                                             Name: Brian J. Walsh
                                             Title: AVP

                                             Address:

                                             6260 East Mockingbird Lane
                                             2nd Floor Mail Code 6592
                                             Dallas, Texas 75214
                                             Telecopy No. (214) 827-9817

                                             Domestic Lending Office:



                                             Telecopy No.:

                                             Eurocurrency Lending Office:



                                             Telecopy No.: