BMW, Rover's parent company, expressed surprise yesterday that its fellow German carmaker, Porsche, is to challenge BMW's £152m government subsidy to rebuild the Longbridge plant. "We expect this to be settled quickly and in our favour," a spokesman for BMW said, responding to reports that Porsche's lawyers had filed a submission to the European Commission on the grounds that the subsidy breaks EU competition rules. BMW decided to invest £3 billion in the Midlands plant last June, after securing government aid to help the company produce a new series of medium-sized cars there. The European Commission is currently investigating the subsidy, and is expected to focus specifically on whether BMW genuinely considered relocating its production from Longbridge to Hungary, as the company claims. A war of words between BMW and Rover could delay the Commission's probe, which in turn could hamper BMW's plans for Longbridge.