Brent ended up 0.82% at $51.50 and WTI ended up 1.11% in New York.

Oil prices continued their march forward on Thursday, reaching new highs since early March at the close, supported by advances on a possible agreement on a new stimulus package in the United States.

A barrel of Brent North Sea oil for February delivery gained 0.82% or 42 cents in London from Wednesday's close at $51.50.

The US barrel of WTI for the month of January for its part appreciated by 1.11% or 54 cents to 48.36 dollars in New York.

The elected members of the United States Congress began marathon negotiations at the start of the week to reach a compromise on new aid measures for American companies and homes hit by the recession.

Democratic and Republican parliamentarians are trying to agree before Christmas on a common and final version of the 908 billion dollar proposal put in place by a group of bipartisan elected officials.

A new aid plan is all the more urgent as new jobless claims jumped again in the United States last week, with 885,000 people having applied for unemployment benefit for the first time.

This is an increase of 23,000 people from the previous week, according to weekly figures from the Labor Department released Thursday.

"It's not just US stimulus hopes that are driving up prices, US inventory data has also given a positive boost," said analyst Barbara Lambrecht. of Commerzbank.

According to a report from the US Energy Information Agency (EIA) released the day before, commercial crude inventories in the United States fell by 3.1 million barrels (MB) in the week ended 11 December, a slightly larger decline than that forecast by analysts.

A “relief”, according to Ms. Lambrecht, after the spectacular rise in these same reserves a week earlier, which had taken the markets by surprise.