U.S. oil prices fell for a fifth straight session and settled at a five-month low on May 17. U.S. crude for June delivery fell $1.53 to settle at $70.08.

After U.S. oil futures hit a 19-month high at $87.15 on May 3, worries about Europe's debt problems and high oil inventories pushed crude futures prices as low as $69.27 on May 17, a 20.5 percent drop from that May 3 peak and their weakest since Dec. 14, 2009.

The euro tumbled against the dollar for a fifth straight session, dropping to a four-year low. A strong U.S. currency often pressures commodities by making dollar-denominated commodities, such as oil, more costly for holders of other currencies and by attracting investors out of commodities and into the foreign exchange market.

Stockpiles of crude at Cushing, Okla., the delivery hub for the U.S. contract's West Texas Intermediate benchmark crude, have risen in the last eight weeks to a record high 37 million barrels, pushing front-month U.S. crude down relative to later futures contracts and the other global crude benchmark, Brent.

The market will get the weekly U.S. oil inventory snapshots from industry and government, starting with the American Petroleum Institute's report on Tuesday afternoon.

Analysts surveyed by Reuters on Monday expected crude oil and distillate stocks to have increased last week, while gasoline stocks were expected to have declined.