Offer Update

Antofagasta PLC 28 April 2006 Tethyan takeover offer reaches compulsory acquisition threshold 28 April 2006 As of 9am, Sydney, Australia time today, Antofagasta PLC ('Antofagasta') had secured a relevant interest in 91% of shares in Tethyan Copper Company Limited ('Tethyan'). Antofagasta's unconditional takeover offer will close at 7pm today, Sydney, Australia time. After the close of the takeover offer, Antofagasta will compulsorily acquire any remaining Tethyan shares in which it does not have a relevant interest. It should be noted that for Tethyan shareholders who accept the offer by the closing date, payment will be despatched to them no later than 19 May 2006. However, payment for Tethyan shares acquired under the compulsory acquisition process will not be made before 1 June 2006. Accordingly, Antofagasta encourages all remaining Tethyan shareholders to accept the offer by 7pm today, Sydney, Australia time. Enquiries - London Enquiries - Santiago Antofagasta PLC Antofagasta Minerals S.A. Tel: +44 20 7808 0988 Alejandro Rivera www.antofagasta.co.uk Tel: +56 2 377 5145 Email: arivera@aminerals.cl Desmond O'Conor Email: doconor@antofagasta.co.uk Enquiries - Australia Bankside Consultants N M Rothschild & Sons (Australia) Ltd Tel: +44 20 7367 8873 (financial advisers) Mob: +44 7885 356 639 Tel: +61 2 9323 2000 Marshall Baillieu Chris Forman Keith Irons Email: keith@bankside.com Oliver Winters Jackson Wells Morris (public relations advisers) Email: oliver.winters@bankside.com Tel: +61 2 9904 4333 Benjamin Haslem Jakob Webster This information is provided by RNS The company news service from the London Stock Exchange

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Antofagasta (ANTO)
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