Morgan Stanley will exit an oil marketing deal with European refineries of Britain's Ineos Group Ltd , now half-owned by PetroChina Co Ltd <0857.HK><601857.SS>, from the end of this month as the Chinese state oil giant takes over the job, traders said.

Morgan Stanley's deal expires on March 31. It's a done deal, said a trader with direct knowledge of the situation.

PetroChina's trading arm Chinaoil will assume the marketing role to secure crude and market refined fuels for the two European refineries jointly owned by Ineos and PetroChina, with a combined daily processing capacity of 420,000 barrels.

It's logical for PetroChina to take over the job as the purpose of (PetroChina) buying up the refineries is to expand the company's global trading portfolio, said a second trader with knowledge of the deal.

Morgan Stanley entered the deal in 2007 with Ineos to provide crude, market refined fuel and provide risk management for the British group's refineries in Grangemouth, Scotland and Lavera in France.

PetroChina bought half of the refining assets last year for $1 billion, the Chinese energy giant's third refinery acquisition after similar investments in Singapore and Japan.

(Editing by Chris Lewis)