Lehman Brothers has suspended two traders in its London offices amid an inquiry into how trades were handled or priced in its equities unit, according to people familiar with the situation.

UK markets regulator, the Financial Services Authority, has been apprised of the situation and the firm is cooperating with its inquiry, these people said. The inquiry is focused on the valuation of securities, likely those tied to equity derivatives, in markets that have seen a significant drop in liquidity, these people said.