Geneva, Wednesday Zairean rebels have asked Switzerland to freeze the assets of President Mobutu Sese Seko and the Swiss have agreed to consider the request.

UN officials say Mobutu's overseas fortune - $4bn according to Swiss media - could be a key factor in the crisis gripping his Central African state, where the president is under international pressure to step down.

The future of his wealth has been mentioned ''informally'' during Mobutu's inconclusive talks with rebel leader Laurent Kabila, senior UN officials say.

But some Swiss are warning that the haven this country provides for huge sums acquired by African dictators could turn into another banking scandal. - Reuter