Lonmin on Wednesday rejected an unsolicited £5bn ($9.8bn, €6.3bn) takeover proposal from Switzerland-based miner Xstrata, which earlier unveiled a proposed £33 a share cash offer for the FTSE 100-listed platinum producer.

Xstrata, which has grown through acquisition over the past five years, has been looking at Lonmin for some time, and appears to be taking the recent fall in the platinum group's shares – down 26 per cent over the past year – as a chance to make a move.