Offer for Equatorial Mining

Antofagasta PLC
15 August 2006



                                ANTOFAGASTA PLC


Antofagasta announces A$11.20 per share cash offer for Equatorial Mining Limited



LONDON: 15 August 2006 - Antofagasta PLC ('Antofagasta') is pleased to announce
it has entered into an agreement to acquire a 19.99 per cent. shareholding in
Equatorial Mining Limited ('Equatorial') and has made a cash takeover offer of
A$11.20 per share for all of the issued shares of Equatorial ('the Offer').



Equatorial is listed on the Australian Stock Exchange and majority owned by AMP
Life Limited ('AMP'), a major Australian financial institution.  Equatorial's
principal asset is its 39 per cent. ownership interest in the El Tesoro copper
mine in Region II of Chile.  Antofagasta owns the remaining 61 per cent.
interest in El Tesoro and has operated and managed the mine since development
began in 1999.  The acquisition of Equatorial would provide Antofagasta with
full ownership of El Tesoro and will consolidate its land position in the Sierra
Gorda district, where its other interests include the Esperanza project.



The Offer represents an attractive price to the shareholders of Equatorial and
an opportunity for them to exit an illiquid investment with cash consideration.
Antofagasta's cash takeover offer is more than 20% higher than the offer
announced by Quadra Mining Ltd ('Quadra') on 20 July 2006 and has considerably
fewer conditions.



The Offer represents a premium of:

•      21 per cent. to Quadra's offer of A$9.26 per share; and

•      60 per cent. to Equatorial's share price on 19 July 2006, the closing
price on the last day prior to the announcement of Quadra's offer.



Antofagasta has entered into an agreement with AMP to acquire a 19.99 per cent.
shareholding in Equatorial at A$8.00 per share.  Accordingly, the total
consideration payable by Antofagasta to acquire all of Equatorial's shares would
be approximately A$527 million (US$401 million).  Equatorial reported cash
balances of A$127 million (US$97 million) as at 30 June 2006.



Marcelo Awad, CEO of Antofagasta Minerals S.A., stated, 'We have enjoyed an
excellent working relationship with Equatorial Mining at El Tesoro since the
initial development of the mine in 1999.  The acquisition of Equatorial will
give Antofagasta outright ownership of El Tesoro and increase our attributable
share of copper production from a quality asset which we know and understand
very well.  Additionally, full ownership of El Tesoro will complement our
existing exploration and development interests in the Sierra Gorda district and
provide Antofagasta with the flexibility to optimise both the scheduling of
projects and associated capital investment decisions.'



The Offer will be made by Sierra Gorda Copper Pty Limited, a wholly owned
subsidiary of Antofagasta, by way of an off-market takeover bid under the
Australian Corporations Act 2001.  The Offer will be funded from Antofagasta's
existing cash resources.



The Offer is conditional on acquiring at least 75 per cent of the number of
outstanding ordinary shares in Equatorial and approval from the Foreign
Investment Review Board in Australia.  The conditions of the Offer are outlined
in Appendix 1 to this press release.



Antofagasta has also entered into an agreement with AMP, whereby AMP has agreed
to pay Antofagasta a break-fee of A$4 million in the event that AMP do not
accept Antofagasta's Offer for the remainder of its shareholding in Equatorial.



Antofagasta commenced the despatch of its Bidder's Statement to Equatorial
shareholders today in Sydney, Australia.



Rothschild is acting as financial adviser and Minter Ellison is acting as legal
adviser in relation to the Offer.


                                        Enquiries - Chile / North America

Enquiries - UK

                                        Antofagasta Minerals S.A.
Antofagasta PLC                         Alejandro Rivera
Tel: [phone]                   Tel: [phone]
www.antofagasta.co.uk                   Email: [e-mail]


Hussein Barma                           Rothschild Inc. (financial adviser)
Email : [e-mail]        Tel: [phone]

                                        Hugo Dryland
Bankside Consultants
Tel: [phone]                   Enquiries - Australia
Mob: [phone]

                                        Rothschild Australia (financial adviser)
Keith Irons                             Tel: [phone]
Email: [e-mail]               Marshall Baillieu
                                        Chris Forman






About Antofagasta PLC

Antofagasta is a Chilean-based mining group listed on the London Stock Exchange
and is a constituent of the FTSE-100 index.  Its principal mining assets include
the Los Pelambres, El Tesoro and Michilla mines and the Esperanza copper
project.  In addition to copper mining, Antofagasta's interests include rail and
road transport operations and water distribution.

About Equatorial Mining Limited

Equatorial is an Australian company listed on the Australian Stock Exchange and
its primary asset is its 39% ownership interest in Minera El Tesoro, a Chilean
company which owns and operates the El Tesoro copper mine.  Equatorial's other
assets include ownership interests in two exploration tenements in the vicinity
of El Tesoro and the rights to extract ground water from the Calama aquifer,
also in the same region.

For the year ended 31 December 2005, Equatorial reported net profit before tax
of A$68.4 million.  Equatorial reported gross assets of A$263 million as at 31
December 2005.

El Tesoro is an open pit mine and heap leach and solvent extraction and electro
winning operation producing LME grade A copper cathode.  For the year ended 31
December 2005, El Tesoro produced 98,100 tonnes of copper cathode (100% terms).
Proven and probable reserves of El Tesoro as of 31 December 2005 were 123.1
million tonnes at a grade of 0.79% Cu using a 0.41% Cu cut-off grade (100%
terms).

Other

Rothschild Inc. and Rothschild Australia Limited are advising Antofagasta and no
one else in relation to the Offer and will not be responsible to anyone other
than Antofagasta for providing the protections afforded to clients of Rothschild
Inc. or Rothschild Australia Limited nor for providing advice in relation to the
Offer.





Appendix 1

Conditions of the Offer



The Offer, and any contract resulting from the acceptance of the Offer, are
subject to the following conditions:



(a)              Minimum acceptance

Before the end of the Offer Period, Sierra Gorda Copper Pty Limited and its
associates have relevant interests in at least 75% of the Equatorial Shares.



(b)             FIRB

One of the following occurs before the end of the Offer Period:

(i)                 Antofagasta PLC or Sierra Gorda Copper Pty Limited receives
written notice issued by or on behalf of the Treasurer stating that there are no
objections under the Australian government's foreign investment policy to the
acquisition by Sierra Gorda Copper Pty Limited of all of the Equatorial Shares
under the Offer, such notice being unconditional;

(ii)               the expiry of the period provided under the Foreign
Acquisitions and Takeovers Act 1975 (Cth) (FATA) during which the Treasurer may
make an order or an interim order under the FATA prohibiting the acquisition of
Equatorial Shares under the Offer, without such an order being made; or

(iii)              if an interim order is made under the FATA to prohibit the
acquisition of Equatorial Shares under the Offer, the subsequent period for
making a final order has elapsed, without any such final order being made.

Ends


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