The ruling puts an end to the six-year-old deal which gives Metro publisher Associated Newspapers exclusive rights to distribute its free paper on the Tube.

The decision opens the way for Express Newspapers boss Richard Desmond to make a bid to launch a long-awaited afternoon freesheet.

The working title for the paper is understood to be London-i, and it would probably be printed at West Ferry.

News International, which publishes The Sun and The Times, is also understood to be planning a bid for the afternoon contract.

Mayor Ken Livingstone, who recently pre-empted the OFT's decision by inviting bids for the afternoon distribution contract, welcomed the news.

But he warned: "Of course, the exclusivity for morning distribution has not been lifted and we will reserve our right to press for this to be removed."