Rio Tinto--Western Australian Diamond Trust Compulsory Acquisition of Units at A$2.00 per unit.

Business Editors

LONDON--(BUSINESS WIRE)--May 9, 2001

Rio Tinto (NYSE: RTP). Rio Tinto Limited (through its wholly owned subsidiary, Capricorn Diamonds Investments Pty Limited) intends to compulsorily acquire all of the outstanding units in Western Australian Diamond Trust (WADT) that it does not already own, as permitted by the Corporations Law.

Rio Tinto currently has a beneficial interest in 96.95% of the issued units of WADT, whose principal asset is a 5% interest in the Argyle Diamond Mines Joint Venture.

Rio Tinto believes that the cash acquisition price of A$2.00 per unit is extremely fair for unitholders because:

- it represents a significant premium of 72% to the preferred valuation of
A$1.16 per unit ascribed to the units by an Independent Expert commissioned to
provide a valuation of WADT;

- the Independent Expert has concluded that Rio Tinto's cash offer
provides fair value for the units;

- it provides unitholders an opportunity to realise a return on securities that
have exhibited a volatile trading history. Over the 12 months to 30 April 2001,
the unit price has traded as low as A$1.26 and as high as A$2.40. Rio Tinto
considers the volume-weighted average price for this period of A$2.0085 to be a
reasonable benchmark for its offer of A$2.00 per unit; and

- it provides unitholders an opportunity to realise full value for securities
that have limited liquidity. Trading volumes on ASX for WADT units are very
poor. In the period from 1 January 2001 to 30 April 2001, average weekly
trading volume for the units was less than 4,000 units per week.

The Notice of Compulsory Acquisition and an Independent Expert's Report prepared by AMC Corporate Pty Ltd (an expert nominated by the Australian Securities & Investments Commission) is being mailed to WADT unitholders.

WADT is registered as a managed investment scheme under the Corporations Law for which the responsible entity is AML Nominees Limited, a wholly owned subsidiary of Ashton Mining Limited. Rio Tinto acquired all of the issued shares in Ashton in early 2001.