<PAGE>

                                                                    EXHIBIT 4.74

THIS NOVATION AGREEMENT is made as of this 24th day of June, 2004 AMONG;

(A)   J Aron & Company (the "REMAINING PARTY");

(B)   Eskom Holdings Limited (formerly Eskom) (the "OLD PARTY"); and

(C)   Investec Bank Limited (the "NEW PARTY").

(1)   The Old Party and the Remaining Party have entered into one or more
      transactions (each, an "OLD TRANSACTION") as identified in the attached
      Annex 1 (hereafter, "OLD TRANSACTIONS" shall refer to any one or more such
      Old Transactions as the context requires), pursuant to and governed by an
      ISDA Master Agreement dated as of 18 November 1999 (the "OLD AGREEMENT").

(2)   The Remaining Party and the New Party have entered into an ISDA Master
      Agreement (the "NEW AGREEMENT") dated as of 16 January 1997.

(3)   With effect from and including 28 June 2004 (the "NOVATION DATE") the Old
      Party wishes to transfer by novation to the New Party, and the New Party
      wishes to accept the transfer by novation of, all of the rights,
      liabilities, duties and obligations of the Old Party under and in respect
      of each Old Transaction, with the effect that the Remaining Party and the
      New Party enter into a new transaction (each, a "NEW TRANSACTION") under
      the New Agreement, as evidenced by a new confirmation as shown in the
      attached Annex 2 ( the "NEW CONFIRMATION") each New Transaction having
      terms identical to an Old Transaction ( but so as not to duplicate
      trades), as more particularly described below (hereafter, "NEW
      TRANSACTIONS" shall refer to any one or more such New Transactions
      replacing such corresponding Old Transactions as the context requires).

(4)   The Remaining Party wishes to accept the New Party as its sole
      counterparty with respect to the New Transactions.

(5)   The Old Party and the Remaining Party wish to have released and
      discharged, as a result and to the extent of the transfer described above,
      their respective obligations under and in respect of the Old Transactions.

Accordingly, the parties agree as follows:

1.    DEFINITIONS.

      Terms defined in the New Agreement are used herein as so defined, unless
      otherwise provided herein.

<PAGE>

2.    TRANSFER, RELEASE, DISCHARGE AND UNDERTAKINGS.

      With effect from and including the Novation Date and in consideration of
      the mutual representations, warranties and covenants contained in this
      Novation Agreement and other good and valuable consideration (the receipt
      and sufficiency of which are hereby acknowledged by each of the parties):

      (a)   the Remaining Party and the Old Party are each released and
            discharged from further obligations to each other with respect to
            each Old Transaction and their respective rights against each other
            thereunder are cancelled, provided that such release and discharge
            shall not affect any rights, liabilities, or obligations of the
            Remaining Party or the Old Party with respect to payments or other
            obligations due and payable or due to be performed on or prior to
            the Novation Date, and all such payments and obligations described
            in this subparagraph (a) shall be paid or performed as between the
            Remaining Party and the Old Party.

      (b)   in respect of each New Transaction, the Remaining Party and the New
            Party each undertake liabilities and obligations towards the other
            and acquire rights against each other (save for any rights,
            liabilities or obligations of the Remaining Party or the New Party
            with respect to payments or other obligations due and payable or due
            to be performed on or prior to the Novation Date identical in their
            terms to each corresponding Old Transaction (and, for the avoidance
            of doubt, as if the New Party were the Old Party and with the
            Remaining Party remaining the Remaining Party);

      (c)   any payments due and payable or obligations due to be performed on
            or prior to the Novation Date but stated in the New Confirmation to
            have accrued with respect to a calculation period (however defined)
            ending after the Novation Date shall be paid or performed between
            the Remaining Party and the New Party, subparagraphs (a) and (b)
            above notwithstanding; and

      (d)   each New Transaction shall be governed by and form part of the New
            Agreement and the New Party and the Remaining Party shall enter into
            the New Confirmation specifying the terms of the New Transactions;
            provided, however, that any failure of either the New Party or the
            Remaining Party to fulfill the terms of the preceding clause shall
            not affect the rights and obligations of the Old Party pursuant to
            this Novation Agreement, and the office of the New Party for
            purposes of each new Transaction shall be as specified in the Annex.

3.    REPRESENTATIONS AND WARRANTIES.

      (a)   Each of the parties makes those representations and warranties set
            forth in Sections 3(a)(ii) through (v) of the New Agreement with
            such changes as shall be required in order for such representations
            to apply with respect to this Novation Agreement alone.

                                        2
<PAGE>

      (b)   The Remaining Party and the Old Party shall each make to the other,
            and the Remaining Party and the New Party shall each make to the
            other, the representation set forth in Scotian 3(b) of the New
            Agreement, in each case with respect to the Old Agreement or the New
            Agreement, as the case may be, and taking into account the parties
            entering into and performing their obligations under this Novation
            Agreement.

      (c)   Each of the Old Party and the Remaining Party represents and
            warrants that:

            (i)   it has made no prior transfer (whether by way of security or
                  otherwise) of the Old Agreement or any interest or obligation
                  in or under the Old Agreement or in respect of any Old
                  Transaction; and

            (ii)  as of the Novation Date, all obligations of the Old Party and
                  the Remaining Party under each Old Transaction required to be
                  performed on or before the Novation Date have been fulfilled.

      (d)   The Old Party makes no representation or warranty or assumes any
            responsibility with respect to the legality, validity,
            effectiveness, adequacy or enforceability of the New Transactions or
            the New Agreement or any documents relating thereto and assumes no
            responsibility for the condition, financial or other, of the
            Remaining Party or any other person or for the performance and
            observance by the Remaining Party of any of its obligations under
            the New Transactions or the New Agreement or any document relating
            thereto and any and all such conditions and warranties, whether
            express or implied by law or otherwise, are hereby excluded.

4.    COUNTERPARTS.

      This Novation Agreement (and each amendment, modification and waiver in
      respect of it) may be executed and delivered in counterparts (including by
      facsimile transmission), each of which will be deemed an original.

5.    COSTS AND EXPENSES.

      The parties will each pay their own costs and expenses (including legal
      fees) incurred in connection with this Novation Agreement and as a result
      of the negotiation, preparation and execution of this Navation Agreement.

6.    AMENDMENTS.

      No amendment, modification or waiver in respect of this Novation Agreement
      will be effective unless in writing (including a writing evidenced by a
      facsimile transmission) and executed by each of the parties or confirmed
      by an exchange of telexes or electronic messages on an electronic
      messaging system.

                                        3
<PAGE>

7.    (a)   GOVERNING LAW.

            This Novation Agreement will be governed by and construed in
            accordance with the laws of England.

      (b)   JURISDICTION.

            The terms of Section 13(b) of the New Agreement shall apply to this
            Novation Agreement with such changes as shall be required in order
            for such terms to apply with respect to this Novation Agreement
            alone.

                                        4
<PAGE>

IN WITNESS WHEREOF the parties have executed this Novation Agreement on the
respective dates specified below with effect from the date specified on the
first page of this Novation Agreement.

     ESKOM HOLDINGS LIMITED                         INVESTEC BANK LIMITED
        (FORMERLY ESKOM)

     By: ___________________________                By: ________________________

              Name:                                          Name:
              Title:                                         Title:
              Date:                                          Date:

     J ARON & COMPANY

     By: ___________________________

              Name:
              Title:
              Date:

                                        5
<PAGE>

                                     ANNEX 1
                                OLD TRANSACTIONS

ZAR GOLD SWAPS

Fixed Price Payer:                  J Aron & Company ("Aron")

Floating Price Payer:               Eskom Holdings Limited ("Eskom")

Commodity:                          Gold (minimum 0.995 fine, London good
                                    delivery form)

Calculation Periods:                6 consecutive monthly periods from and
                                    including the Effective Date to and
                                    including the Termination Date as specified
                                    in Table 1 below.

Effective Date:                     1 July 2004

Termination Date:                   31 December 2004

Payment Dates:                      With respect to each Calculation Period, the
                                    15th day of the immediately following
                                    Calculation Period (See Table 1 below).

Quantity per Calculation Period:    15,000 fine troy ounces

Fixed Price Levels:                 (A) ZAR 2,192.00 per fine troy ounce for
                                    each Calculation Period from and including
                                    the July 2004 to and including the September
                                    2004 Calculation Period

                                    (B) ZAR 2,256.00 per fine troy ounce for
                                    each Calculation Period from and including
                                    the October 2004 to and including the
                                    December 2004 Calculation Period

Floating Price:                     With respect to each Calculation Period the
                                    Floating Price shall be equal to the
                                    arithmetic average of the Commodity
                                    Reference Prices for each Business Day in
                                    such Calculation Period.

Commodity Reference Price:          The London A.M. Fix converted to ZAR at the
                                    mid price of 'Ccy Snaps at the time of
                                    fixing' published on Reuters page 'GOFO'

Payment Calculation:                (a) If for a Calculation Period the Fixed
                                    Price is greater than the Floating Price,
                                    Aron shall pay Eskom an amount equal to the
                                    product of:

                                      (i)  the difference between the Fixed
                                           Price and the Floating Price, and

                                      (ii) the Quantity for the applicable
                                           Calculation Period.

                                    (b) If for a Calculation Period the Floating
                                    Price is greater than the Fixed Price, Eskom
                                    shall pay Aron an amount equal to the
                                    product of:

                                      (i)  the difference between the Floating
                                           Price and the Fixed Price, and

                                      (ii) the quantity for the applicable
                                           Calculation Period.

Settlement:                         Cash Settlement on the applicable Payment
                                    Date provided, however, that if any of the
                                    foregoing is not a Business Day the
                                    applicable Value Date shall be the
                                    immediately following Business Day.

                                        6
<PAGE>

TABLE 1.

<TABLE>
<CAPTION>
                             Calculation
Calculation Period              Period                 Payment
    Start Date                 End Date                 Date
------------------           ------------            ---------
<S>                          <C>                     <C>
01-Jul-04                      30-Jul-04             16-Aug-04
02-Aug-04                      31-Aug-04             15-Sep-04
01-Sep-04                      30-Sep-04             15-Oct-04
01-Oct-04                      29-Oct-04             15-Nov-04
01-Nov-04                      30-Nov-04             15-Dec-04
01-Dec-04                      31-Dec-04             18-Jan-05
</TABLE>

OTHER PROVISIONS:

Business Days:                      For Pricing - London and Johannesburg
                                    For Settlement  - New York and Johannesburg

Calculation Agent:                  Aron

Fallback Prices/Rate:               If any rate or price referenced above is
                                    unavailable as of the applicable time on a
                                    Business Day or would not produce a
                                    commercially reasonable result then such
                                    rate shall be determined by agreement
                                    between the parties and failing that, Aron
                                    will determine the rate acting in good faith
                                    and in a commercially reasonable manner.

                                        7
<PAGE>

                                     ANNEX 2
                                NEW CONFIRMATION

ZAR GOLD SWAPS

Fixed Price Payer:                  J Aron & Company ("Aron")

Floating Price Payer:               Invested Bank Limited ("Investec")

Commodity:                          Gold (minimum 0.995 fine, London good
                                    delivery form)

Calculation Periods:                6 consecutive monthly periods from and
                                    including the Effective Date to and
                                    including the Termination Date as specified
                                    in Table 1 below

Effective Date:                     1 July 2004

Termination Date:                   31 December 2004

Payment Dates:                      With respect to each Calculation Period, the
                                    15th day of the immediately following
                                    Calculation Period (See Table 1 below).

Quantity per Calculation Period:    15,000 fine troy ounces

Fixed Price Levels:                 (A) ZAR 2,192.00 per fine troy ounce for
                                    each Calculation Period from and including
                                    the July 2004 to and including the September
                                    2004 Calculation Period

                                    (B) ZAR 2,256.00 per fine troy ounce for
                                    each Calculation Period from and including
                                    the October 2004 to and including the
                                    December 2004 Calculation Period

Floating Price:                     With respect to each Calculation Period the
                                    Floating Price shall be equal to the
                                    arithmetic average of the Commodity
                                    Reference Prices for each Business Day in
                                    such Calculation Period.

Commodity Reference Price:          The London A.M. Fix converted to ZAR at the
                                    mid price of 'Ccy Snaps at the time of
                                    fixing' published on Reuters page 'GOFO'

Payment Calculation:                (a) If for a Calculation Period the Fixed
                                    Price is greater than the Floating Price,
                                    Aron shall pay Investec an amount equal to
                                    the product of:

                                      (i)  the difference between the Fixed
                                           Price and the Floating Price, and

                                      (ii) the Quantity for the applicable
                                           Calculation Period.

                                    (b) If for a Calculation Period the Floating
                                    Price is greater than the Fixed price,
                                    Investec shall pay Aron an amount equal to
                                    the product of:

                                      (iii)the difference between the Floating
                                           Price and the Fixed Price, and

                                      (iv) the Quantity for the applicable
                                           Calculation Period.

Settlement:                         Cash Settlement on the applicable Payment
                                    Date provided, however, that if any of the
                                    foregoing is not a Business Day the
                                    applicable Value Date shall be the
                                    immediately following Business Day.

                                        8
<PAGE>

TABLE 1.

<TABLE>
<CAPTION>
                              Calculation
Calculation Period              Period
   Start Date                  End Date            Payment Date
------------------            -----------          ------------
<S>                           <C>                  <C>
01-Jul-04                      30-Jul-04             16-Aug-04
02-Aug-04                      31-Aug-04             15-Sep-04
01-Sep-04                      30-Sep-04             15-Oct-04
01-Oct-04                      29-Oct-04             15-Nov-04
01-Nov-04                      30-Nov-04             15-Dec-04
01-Dec-04                      31-Dec-04             18-Jan-05
</TABLE>

OTHER PROVISIONS:

Business Days:                      For Pricing - London and Johannesburg For
                                    Settlement - New York and Johannesburg

Calculation Agent:                  Aron

Fallback Prices/Rate:               If any rate or price referenced above is
                                    unavailable as of the applicable time on a
                                    Business Day or would not produce a
                                    commercially reasonable result then such
                                    rate shall be determined by agreement
                                    between the parties and failing that, Aron
                                    will determine the rate acting in good faith
                                    and in a commercially reasonable manner.

                                        9