The UK's participation will be seen as a milestone in the progress of the convention

Professor Norman Palmer

The international agreement will make it easier for countries to reclaim stolen works of art which surface in the territories of fellow signatories.

It is thought the trade costs the UK up to �150m per year in insured losses.

'Important step'

Arts Minister Alan Howarth said: "The signing of the convention is undoubtedly an important step but there is more to come.

"My department is also working closely with the Home Office to examine the feasibility of establishing a database of stolen and illegally removed cultural property."

Police believe that criminals launder profits through untraceable stolen goods.

The legal UK market in cultural objects is the second largest in the world, accounting for 30% of the global art market.

'Delighted'

Professor Norman Palmer, who headed an advisory panel to the government on the stolen art trade, welcome the decision.

The University College of London professor said: "I am delighted to learn that the UK has signed up to the Unesco convention.

"The UK's participation, I believe, will be seen as a milestone in the progress of the convention."

Last year a �3m painting by French impressionist Paul Cezanne was stolen from an Oxford museum.

Auvers-sur-Oise, an oil on canvas dated between 1879 and 1882, is believed to have been stolen to order on behalf of a crooked collector.