A planned shake-up of ferry services on the Irish Sea moved a step closer yesterday after operators P&O and Stena exchanged contracts on a landmark deal.

The move formalises plans set out earlier this year which could see about 200 P&O staff transfer to Stena in a major overhaul of services linking Northern Ireland and the Republic with the British mainland.

P&O plans to sell £50m of P&O assets, including five ferries and port facilities in Liverpool, Fleetwood and Dublin at book price to Stena, while a joint venture between the two will buy P&O's interests in Cairnryan, south-west Scotland.

P&O said the overall deal, part of a new focus on higher-yielding routes, would not result in a significant financial gain or loss.

Despite the exchange of contracts, the deal cannot go ahead until after a Competition Commission investigation into key elements of the plans