P&O Ferries has signed a £282million contract with Aker Yards for the two largest ferries ever to be constructed for the Dover-Calais service - and says it may order two more.

The first of these ships will enter service in December 2010 and the second in September 2011, replacing the Pride of Dover and the Pride of Calais. They will be built at the Aker shipyard in Rauma, Finland.

The company has taken options on a further two vessels of the same design.

At 49,000 gross tonnes and 210 metres in length, the ferries will be the largest ships capable of fitting into existing facilities in the Channel ports and will be the first Channel ferries designed to manoeuvre under their own power in 50 knot winds.

They will have space for more than 180 freight vehicles, more than doubling the freight carrying capacity of the ships they are replacing, whilst additionally providing a third vehicle deck for up to 195 tourist vehicles. They will be able to carry up to 2,000 passengers.

P&O Ferries chairman Robert Woods said: "These ships will be as environmentally friendly as possible."