Purchase of Shares

Antofagasta PLC
24 February 2006


news release

For immediate release: 24 February 2006

                                Antofagasta plc

          Antofagasta announces purchase of 8.94% interest in Tethyan

London, 24 February 2006: Further to its announcement on 14 February 2006 of a
recommended cash offer for Tethyan Copper Company Limited ('Tethyan'),
Antofagasta PLC ('Antofagasta') is pleased to announce that it has today filed
with the Australian Stock Exchange a Notice of Initial Substantial Holder which
discloses the purchase by Antofagasta of 11,842,910 Tethyan shares in the market
between 20 and 23 February 2006.  This represents an interest of 8.94% in
Tethyan's issued share capital.

Antofagasta's Bidder's Statement is expected to be lodged with the Australian
Securities and Investment Commission and to be dispatched to Tethyan 
shareholders as soon as practicable.

Rothschild is advising Antofagasta in relation to this transaction.

Enquiries - London

Antofagasta PLC
Tel: [phone]
www.antofagasta.co.uk
Desmond O'Conor
Email: [e-mail]


Bankside Consultants
Tel: [phone]
Keith Irons
Email: [e-mail]


Enquiries - Santiago

Antofagasta Minerals S.A.
Alejandro Rivera
Tel: [phone]
Email: [e-mail]


Enquiries - Australia

N M Rothschild (Australia) Ltd (financial advisers)
Tel: [phone]
Marshall Baillieu
Chris Forman


Jackson Wells Morris (public relations advisers)
Tel: [phone]
Benjamin Haslem


Details of on-market purchases of Tethyan shares

Date of acquisition                      Consideration                 Number of
---------------------                       ------------                shares
                                                                  --------------

20 February 2006                           A$5,167,491               4,310,553
21 February 2006                             A$823,613                 689,447
23 February 2006                           A$8,208,755               6,842,910



About Antofagasta PLC

Antofagasta PLC 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 Tethyan Copper Company Limited

Tethyan is a company listed on the Australian Stock Exchange. Its principal
assets are a 75% interest in the exploration licence encompassing the highly
prospective Chagai Hills region of North West Pakistan known as Reko Diq, which
includes the Tanjeel Mineral Resource and the Western Porphyries, and a 100%
interest in certain other licences in the region. This mining district hosts
significant copper-gold porphyry deposits as part of an extended copper-gold
belt. Tethyan has reported total indicated and inferred mineral resource
estimates at these properties of 2.4 billion tonnes with a copper grade of 0.51%
and a gold grade of 0.27 grams per tonne. The resource estimates include
probable reserves at the Tanjeel Mineral Resource of 128.8 million tonnes with a
copper grade of 0.7%. Reserve and resource estimates have been reported by
Tethyan to JORC standards. Tethyan had gross assets of A$28.8 million as at 30
June 2005 and reported a net loss of A$1.7 million for the year ended 30 June
2005.




                      This information is provided by RNS
            The company news service from the London Stock Exchange