Oil prices rose to a six-week high above $80.75 a barrel on Monday, extending the previous session’s gains, as speculation over a quick bailout for debt-laden Greece helped pushed the U.S. dollar lower.

U.S. crude for April delivery rose 54 cents to $80.77 a barrel by 01:45 GMT- the highest since Jan 13. U.S. crude for March delivery rose 42 cents to $80.23 a barrel by 07:37 GMT, after having struck $80.51.

Support to oil prices also resulted from concerns about an extended refinery strike in France and escalating tensions over Iran’s nuclear program.

“The weak dollar is the biggest driver for crude prices this morning and hopes of a financial rescue for Greece are propping up sentiments,” said Clarence Chu, a trader with Hudson Capital Energy in Singapore.

The U.S. dollar index fell 0.18 percent against a basket of currencies on Monday, as investors reassessed chances of an earlier-than-expected interest rate hike by the Federal Reserve while the euro was lifted by speculation of a quick bailout for Greece.

Concern over Athens’ ability to repay its debt mountain has shaken confidence in the euro and stirred fears that it may hinder global growth. Some analysts have said that a plan to rescue Greece would help allay sovereign debt concerns in Europe.

Adding to bullish sentiments was a report by the China Petroleum and Chemical Industry Association (CPCIA) that said China processed 30.14 million tonnes of crude in January, up 29 percent from a year earlier.

Separately, an extended strike at Total’s six oil refineries in France and growing hostility between Iran and the West also aided bullish sentiment for crude. An extended strike would lift Europe’s gasoline prices and also push up prices across the energy complex, market participants said.