<PAGE>
                                                                   EXHIBIT 10(g)
                     DEED OF AMENDMENT AND ACKNOWLEDGMENT

                          DATED:  31ST DECEMBER 1996

                                    BETWEEN

                       CASE CREDIT AUSTRALIA PTY LIMITED
                              A.C.N. 069 132 396

                                      AND

                            CASE CREDIT CORPORATION

                                      AND

                        NATIONAL AUSTRALIA BANK LIMITED
                              A.C.N. 004 044 927





                           DIBBS CROWTHER & OSBORNE
                                  Solicitors
                             50 Carrington Street
                                SYDNEY NSW 2000
                                 OX 101 Sydney
                                 Tel: 290-8200
                                 Fax: 290-2964
                                  Ref: RG/PRE


<PAGE>
 
                                      (I)


                                   CONTENTS



1.   DEFINITIONS AND INTERPRETATION....................................... -1-

2.   CONSIDERATION........................................................ -2-

3.   RELEVANT AGREEMENT................................................... -2-

4.   CONSENT, CONFIRMATION AND ACKNOWLEDGEMENT............................ -2-

5.   AMENDMENT............................................................ -3-
     5.1   Letter of Offer dated 28 September, 1996 from the Bank to
           Case Credit Australia.......................................... -3-
     5.2   Negative Pledge Agreement dated 29 September, 1996
           between Case Credit Australia and the Bank..................... -4-
     5.3   Guarantee and Indemnity........................................ -5-

6.   CONDITIONS PRECEDENT................................................. -5-

7.   REPRESENTATIONS AND WARRANTIES....................................... -5-

8.   MISCELLANEOUS........................................................ -6-

                          SCHEDULE TO LETTER OF OFFER..................... -7-


<PAGE>
 
                     DEED OF AMENDMENT AND ACKNOWLEDGMENT


THIS DEED is made on 31st December 1996,

BETWEEN:  CASE CREDIT AUSTRALIA PTY LIMITED A.C.N. 069 132 396 of 31-87
          Kurrajong Avenue, St Marys, New South Wales, 2760 ("Case Credit
          Australia")

AND:      CASE CREDIT CORPORATION of 621 State Street, Racine, Wisconsin, 53404,
          United States of America ("Case Credit")

AND:      NATIONAL AUSTRALIA BANK LIMITED A.C.N. 004 044 937 of Level 25, 
          National Australia Bank House, 255 George Street, Sydney, New South
          Wales, 2000 ("Bank")

RECITALS:

A.   Under the Bank's Letter of Offer, the Bank agreed to make available
     financial recommodation to the Customer on the terms and conditions set out
     in the Letter of Offer.

B.   The Customer and the Bank entered into a Negative Pledge Agreement which,
     in addition to the Letter of Offer, set out the Customer's obligations to
     the Bank.

C.   In support of the Customer's obligations under the Letter of Offer and the
     Negative Pledge Agreement, Case Credit provided to the Bank the Guarantee
     and Indemnity.

D.   The Customer and Case Credit have requested the Bank to vary the terms of 
     the Facility provided under the terms of the Letter of Offer, the Negative
     Pledge Agreement and the Guarantee and Indemnity.

E.   The Bank has agreed to that request on the basis that the Customer and Case
     Credit deliver to the Bank a deed in the form of this deed.

F.   This deed is collateral to and secures the same moneys and obligations
     under the Facilities as provided for in the Letter of Offer and in the
     Negative Pledge Agreement.

OPERATIVE PROVISIONS:

1.   DEFINITIONS AND INTERPRETATION

     1.1  Words defined in the Negative Pledge Agreement that are not defined in
          this deed have the same meaning given to them in the Negative Pledge
          Agreement unless contrary to or inconsistent with the intention or as
          the context otherwise requires.

     1.2  The provisions of clauses 1.1 (definitions), 1.2 (interpretation),
          __(miscellaneous), __ (notices) and 10 (governing law and
          jurisdiction) of the Negative Pledge Agreement apply to this deed,
          mutatis mutandis, as if they are set out in full in this deed.

     1.3  In this deed (including the Recitals), the following expressions have
          the following meanings unless inconsistent or contrary to the context.

          "Customer" means Case Credit Australia.

          "Guarantee and Indemnity" means a Deed of Guarantee and Indemnity
          dated September 26, 1996 (unconditional) granted by Case Credit in
          favour of the Bank in respect of the obligations of Case Credit
          Australia.

          "Guarantor" means Case Credit.

   
<PAGE>

                                      -2-
 
          "Letter of Offer" means a Letter of Offer dated 28 September, 1996 
          from the Bank to Case Credit Australia.

          "Negative Pledge Agreement" means a Negative Pledge Agreement dated 29
          September, 1996 between Case Credit Australia and the Bank (as varied
          by a letter of amendment dated 19 March, 1996).

2.   CONSIDERATION

     The parties to this deed acknowledge entering into this deed and incurring 
     obligations and granting rights under this deed for valuable consideration.

3.   RELEVANT AGREEMENT

     Each of the parties to this deed acknowledges and agrees with the Bank 
     that:

     (a)  this deed;

     (b)  any other document dated on or before the date of this deed which
          varies or evidences a facility, or any other financial accommodation
          by the Bank to or in favour of the Customer's end

     (c)  all Security interests granted or to be granted from time to time by 
          the Customer to or in favour of the Bank,

     constitute a "Relevant Agreement" unless otherwise agreed to by the Bank.

4.   CONSENT, CONFIRMATION AND ACKNOWLEDGEMENT

     4.1  The Customer and the Guarantor unconditionally and irrevocably consent
          to their entry into, execution of and performance of the terms of
          this deed and the observance by each of them of their respective
          obligations under this deed and the Relevant Agreements.

     4.2  For the removal of doubt, nothing in this deed affects any rights,
          powers or remedies of the Bank which may have accrued to the Bank as a
          result of any set, emission, matter or thing occurring before the date
          of this deed.

     4.3  The Customer and the Guarantor both jointly and severally confirm and
          acknowledge:

          (a)  that the Customer's obligations under the Letter of Offer and
               under the Negative Pledge Agreement (as varied by this deed),
               and the obligations of each person that is a party to a Relevant
               Agreement will continue in full force and affect in accordance
               with their terms notwithstanding the execution and performance of
               this deed;

          (b)  their continuing obligations under the Letter of Offer, the
               Negative Pledge Agreement and the Guarantee and Indemnity and
               acknowledge and agree that, except as varied or supplemented by
               this deed, the Customer's obligations and the Guarantor's
               obligations under the Relevant Agreements to which they are a
               party remain and will continue in full force and effect in
               accordance with their terms; and

          (c)  that the financial accommodation contemplated in the Letter of
               Offer (as amended, varied or supplemented from time to time) is
               or will be (as the case may be) for the benefit of the Customer
               and for the benefit of each person entering into a Relevant
               Agreement.



<PAGE>

                                      -3-

     4.4  The Guarantor acknowledges that all of the terms of the Guarantee and
          Indemnity (except as varied by clause 5.3 of this deed) continue in
          full force and effect to secure the obligations of the Customer to the
          Bank.

5.   AMENDMENT

     Subject to clause 6 of this deed, from the date of this deed the following 
     amendments are made in the following manner:

     5.1  Letter of Offer dated 28 September, 1995 from the Bank to Case Credit 
          Australia

          (a)  the Acceptance and/or Discount Facility

               (i)  The following words are inserted at the end of the paragraph
                    entitled "Purpose":

                    "Otherwise to make funds available to any Group Member on an
                    intercompany loan account basis in order to maximize the
                    Group's cash management flexibility."

               (ii) The paragraph entitled "Line Fee" and the "Activation Fee" 
                    are deleted and replaced with the following provision:

                    "While the Bank continues to have the benefit of the
                    Guarantee and Indemnity given to it by Case Credit
                    Corporation, the Bank will charge to the Company Line Fees
                    and Activation Fees as a direct consequence of Case
                    Corporation's Senior Unsecured Long Term Rating determined
                    by two nationally recognized rating agencies selected by the
                    Company (at least one of which shall be Standard & Poor's or
                    Moody's), in accordance with the pricing grid set out in
                    the schedule to this letter of offer.

                    If the ratings of such nationally recognized rating agencies
                    do not coincide, the Line Fee and Activation Fee set out
                    opposite the higher of such ratings will apply. If at any
                    time an event occurs which results in there being no rating
                    or only one rating in effect, a new Line Fee and Activation
                    Fee will be determined in a manner to be agreed upon by the
                    Bank and the Company and until such new Line Fee and
                    Activation Fee shall be so agreed upon, the relevant fees
                    will be deemed to be the Line Fee and Activation Fee in
                    effect immediately prior to the date on which such event
                    occurs.

                    As at 15 December, 1996, the Line Fees and the Activation 
                    Fees for this facility are:

                       Rating               Line Fee            Activation Fee

                       BBB/Baa2             0.125% p.a.          0.250% p.a.

                    Line Fees are payable quarterly in advance on each 18 March,
                    June, September and December.

                    Activation Fees are calculated on the face value and 
                    tenor of bills drawn and charged upon activation."

          (b)  Stand-by Bill Acceptance and/or Discount Facility

               (i)  The following words are inserted at the end of the paragraph
               entitled "Purpose":


<PAGE>

                                     - 4 -
 
                    "Otherwise to make funds available to any Group Member on an
                    Intercompany loan account basis in order to maximise the
                    Group's cash management flexibility.

               (ii) In the paragraph entitled "Drawdown Conditions" the words,
                    "at least 2 other Banking Days before the day it requires
                    funds" are deleted and replaced with the following words:

                    "at least by 6:00 p.m. on the day before it requires
                    funds".

               (iii)Following the Bank's annual review of this facility at the
                    end of 1996, this facility is extended to 30 November 1997.

               (iv) The paragraph entitled "Line Fee" is deleted and replaced 
                    with the following:

                    "Line Fee:  0.10% per annum on the Limit, payable quarterly
                                in advance on each 15 March, June, September
                                and December".

     5.2  Negative Pledge Agreement dated 29 September, 1995 between Case Credit
Australia and the Bank

               (a)  The definition of "Third Party Receivables" on page 5 of the
                    Negative Pledge Agreement is deleted and replaced with the
                    following:

                    ""Third Party Receivables" means receivables owing to the
                    Customer by any person other than a Related Body Corporate
                    excluding any component of such receivable that comprises
                    unearned finance charges and any provision for bad or
                    doubtful debts".

               (b)  In paragraph (?) of the definition of "Permitted Security
                    Interest" the words, "$100,000 in aggregate" are deleted and
                    replaced with the following words," "$10,000,000 in
                    aggregate".

               (c)  In clause 4.2 "General Undertakings" on page 8 and 9 of
                    the Negative Pledge Agreement, clause 4.2(d) is deleted and
                    replaced with the following new clause 4.2(d):-

                    "(d) net, without first obtaining the Bank's prior written
                         consent (such consent not to be unreasonably withheld),
                         to apply any funds available to it under the Facility
                         for the acquisition of Third Party Receivables where
                         the debtor and/or the equipment to which the Third
                         Party Receivables relate are outside Australia except
                         where the total of the non-Australian Third Party
                         Receivables does not exceed 10% of the aggregate total
                         of Third Party Receivables at any time."

               (d)  In clause 5.1 "financial undertakings" on page 9 of the
                    Negative Pledge Agreement, clause 5.1(a) is deleted and
                    replaced with the following new clause 6.1(a):-

                    "(?) The ratio of Total Liabilities to Shareholders' Funds
                         shall not exceed ?.1 at any time;"

               (e)  The reference to the ratio "1.10:1" in paragraph (b) of
                    clause 6.1 of the Negative Pledge Agreement is deleted and
                    replaced with the ratio "1.05:1".

               (f)  Paragraphs (c) and (d) of clause 5.1 of the Negative Pledge
                    Agreement are deleted.

 
<PAGE>
 
                                      -5-

               (g)  Clause 7.1 (g) of the Negative Pledge Agreement is deleted.

               (h)  Clause 7.4 of the Negative Pledge Agreement is deleted.

     5.3  Guarantee and Indemnity

          (a)  The definition of or reference to the "Revolving Credit
               Agreement" in the Guarantee and Indemnity is deleted and replaced
               with the following new definition or description:-

               ""Case Credit Corporation Revolving Credit and Guarantee
               Agreement" means a document entitled "US $1,200,000,000 Revolving
               Credit and Guarantee Agreement" dated as of August 23, 1996
               between Case Credit Corporation, the foreign subsidiary
               borrowers, the Co-Agents and the Lead Managers named in that
               document and the Chase Manhattan Bank."

          (b)  All references to sections 7.5 and 10 of the Revolving Credit
               Agreement referred to in clause 9 of the Guarantee and Indemnity
               are deleted and replaced with references to sections 8, 10 and 11
               in the Case Credit Corporation Revolving Credit and Guarantee
               Agreement.

6.   CONDITIONS PRECEDENT

     6.1  The variation of the Letter of Offer, the Negative Pledge Agreement
          and the Guarantee and Indemnity contemplated by clause 5 of this deed
          is subject to the condition precedent that the Bank has received the
          following in form and substance reasonably satisfactory to it:

          (a)  the execution and delivery of this deed;

          (b)  a certified copy of each authority under which each party to this
               deed (other than the Bank) signs and delivers this deed (or any 
               other document contemplated by this deed) and if the authority is
               a power of attorney, evidence of its stamping (where required by
               law) and its registration;

          (c)  certified extracts evidencing the resolutions of each party to
               this deed (where relevant) (other than the Bank) approving the
               entry into this deed and authorising execution, delivery and
               observance of obligations under this deed; and

          (d)  such ancillary documents or any other information or document
               (whether originals or copies) which the Bank, in its discretion,
               may request or reasonably considers necessary or desirable to
               examine or hold.

     6.2  It is a further condition precedent to the Bank agreeing to amend the
          Letter of Offer, the Negative Pledge Agreement and the Guarantee and
          Indemnity, as contemplated by clause 6 of this deed, that no Event of
          Default or event which with the giving of notice, lapse of time or any
          determination would be an Event of Default, has occurred or would be
          likely to occur.

7.   REPRESENTATIONS AND WARRANTIES

     7.1  The Customer repeats the representations and warranties in clause 6 of
          the Negative Pledge Agreement for the benefit of the Bank.

     7.2  The Guarantor repeats the representations and warranties in the 
          Guarantee and Indemnity for the benefit of the Bank.

     7.3  The Customer acknowledges that the Bank will be entering into this
          deed in reliance, inter alia, on all of these representations and
          warranties.


             


<PAGE>

                                      -6-
 
8.   MISCELLANEOUS

     8.1  Nothing contained in this deed abrogates, prejudices, diminishes or
          otherwise adversity affects any rights, powers, remedies, obligations
          or liabilities (in any case whether present, future or contingent) in
          relation to any act, matter or thing done or effected or otherwise
          arising in relation to a Relevant Agreement or any documents to which
          the Customer and the Bank are parties before the execution of this
          deed.

     8.2  This deed binds each of the signatories to it even if one or more
          of these persons named in this deed never executes it or that the
          execution by any one or more of those persons (other than the persons
          sought to be made liable under it) is or may become void or voidable.

     8.3  If there is any inconsistency between the terms of this deed and any
          prior communications between the Customer and the Bank, the terms of
          this deed will prevail and the parties acknowledge that this deed
          supersedes in all respects the terms of those prior communications.

     8.4  The Customer agrees to pay to the Bank, and to indemnify and keep
          indemnified the Bank against all and any costs, charges, fees,
          expenses and taxes (including any lost fees or penalties) in relation
          to the preparation, negotiation, settlement, attempting, enforcement
          or attempted enforcement of this deed now and in the future.

     8.5  Each of the covenants of this deed are severable and distinct from one
          another and if at any time any one or more of the provisions of this
          deed is or becomes invalid, illegal or unenforceable in any respect
          under any law, the validity, legality and enforceability of the
          remaining provisions will not in any way be affected or impaired.

     8.6  This deed is governed by the laws in force in New South Wales and each
          party irrevocably and unconditionally submits to the non-exclusive
          jurisdiction of the courts of New South Wales and courts of appeal
          from them.

     8.7  This deed may consist of a number of counterparts and the counterparts
          taken together constitute one and the same instrument.
<PAGE>
 
                                      -7-


                          SCHEDULE TO LETTER OF OFFER

<TABLE> 
<CAPTION> 

Pricing Grid:        Sr. Unsec. L T Rating          Line Fee      Activation Fee
                     Standard & Poors/Moody's      
<S>                  <C>                            <C>           <C> 
                     A/A2 and above                 0.07% p.a.       0.155% p.a.

                     A-/A3                          0.08% p.a.        0.17% p.a.

                     BBB+/Baa1                      0.10% p.a.        0.20% p.a.

                     BBB/Baa2                       0.125% p.a.       0.25% p.a.

                     BBB-/Baa3                      0.175% p.a.      0.275% p.a.

                     BB+/Ba1                        0.25% p.a.       0.425% p.a.

                     Under BB+/Ba1                  0.30% p.a.       0.575% p.a.

</TABLE> 
<PAGE>
                                     - 8 -

EXECUTED as a deed.


The common seal of CASE CREDIT AUSTRALIA PTY LIMITED was affixed in accordance) 
with Its articles of association in the presence of:                          )
                                                                              )
                                                                              )
/s/ Andrew Mour                                                               )
-------------------------------------------                                   )
Signature of authorised person                                                )
                                                                              )
DIRECTOR                                                                      )
-------------------------------------------                                   )
Office held                                                                   )
                                                                              )
/s/ ANDREW MOUR                                                               )
-------------------------------------------                                   )
Name of authorised person                                                     )
(block letters)                                                               )



Signed, sealed and delivered for and on behalf of CASE CREDIT CORPORATION by a)
person duly authorized in that regard in the presence of:                     )
                                                                              )
                                                                              )
/s/ Frank A. Anglin                                                           )
-------------------------------------------                                   )
Signature of Witness                                                          )
                                                                              )
/s/ FRANK A. ANGLIN                                                           )
-------------------------------------------                                   )
Name of Witness (block letters)                                               )



Signed, sealed and delivered by                                               )
                                                                              )
for and on behalf of NATIONAL AUSTRALIA BANK LIMITED under power of attorney  ) 
registered book 5834 number 549 in the presence of:                           )
                                                                              )
                                                                              )
/s/ D. Muter                                                                  )
-------------------------------------------                                   )
Signature of witness                                                          )
                                                                              )
/s/ DARREN MUTER                                                              )
-------------------------------------------                                   )
Name of witness (block letters)                                               )
                                                           



                         [CORPORATE SEAL APPEARS HERE]


/s/ Robert A. Wegner
-------------------------------------------
Signature of authorised person

DIRECTOR
-------------------------------------------
Office held

/s/  ROBERT A. WEGNER
-------------------------------------------
Name of authorised person
(block letters)


/s/  Robert A. Wegner
-------------------------------------------
Signature of authorised person

VICE PRESIDENT
-------------------------------------------
Office held

/s/  ROBERT A. WEGNER
-------------------------------------------
Name of authorised person (block letters)




/s/  Warren James Shaw
-------------------------------------------
By executing this deed the attorney states that the attorney has received no 
notice of revocation of the power of attorney