This excerpt taken from the ELN 6-K filed Apr 11, 2005.
k Foreign currencies and translation of subsidiary and associated undertakings
Transactions in foreign currencies are recorded at the exchange rate prevailing at the date of the transaction. The resulting monetary assets and liabilities are translated into U.S. dollars at exchange rates prevailing at subsequent balance sheet date and the resulting gains and losses are recognised in the profit and loss account and, where material, separately disclosed.
The functional currency of most of our subsidiaries is U.S. dollars. For those subsidiaries with non-U.S. dollars functional currency, their assets and liabilities of subsidiary undertakings are translated using year-end rates and net income is translated at average rates. The cumulative effect of exchange differences arising on consolidation of the net investment in overseas subsidiaries and associates are taken directly to reserves through the Consolidated Statement of Total Recognised Gains and Losses.