However, it remained close to six-month highs with stronger-than-expected German data and tension in Iran helping keep a floor under prices.

Brent crude fell 15 cents to $117.78 a barrel by 1439 GMT.

US crude headed for its highest close in over a month, supported by the prospect of falling supply from Canada. US crude was trading 80 cents up at $101.71 a barrel.

Canadian Natural Resources Ltd. said on Monday its Horizon oil sands plant will not return to full output until mid- to late March, as repairs will take longer than expected.

Rating agency Moody's warned it may cut the triple-A ratings of France, Britain and Austria and it downgraded six other European nations including Italy, Spain and Portugal, citing growing risks from Europe's debt crisis.

But ZEW data from Germany suggested the recovery, which slowed at the end of last year, is back on track.

The better-than-expected German economic data and a successful Italian bond auction eased fears about European demand.

"There is mixed data, and Brent looks a bit bearish today, but the oil price is holding relatively well despite the supply/demand balance looking a bit softer, with the Iran issue at the back of our heads," said Andy Sommer, at EGL in Dietikon, Switzerland.

US retail sales rose less than expected in January as consumers cut back on car purchases and did less online shopping.

MIDDLE EAST VIOLENCE

Oil prices remain underpinned by ongoing tension in the Middle East, with Israel accusing Iran and its Lebanese ally Hezbollah of being behind two bomb attacks that targeted Israeli embassy staff in India and Georgia on Monday.

On Tuesday, an Iranian man was seriously wounded in Bangkok when a bomb he was carrying exploded, police and government officials said, though they declined to speculate on whether he was involved with any military group.

Iran and Israel are already at loggerheads over Tehran's nuclear programme.

Violence also spread in Syria as troops bombarded opposition strongholds, entering a 10th day of shelling and sniper fire in the city.

Meanwhile, oil production and exports from Yemen's Masila oilfield, the country's largest, have stopped after workers from state-owned PetroMasila went on strike last Thursday.

The American Petroleum Institute will release its weekly report on US crude stocks on Tuesday at 2130 GMT.

A Reuters poll of analysts is forecasting a rise in US crude oil inventories for a fourth week in a row due to higher imports and lower refinery utilisation.

On average, domestic crude stockpiles are expected to add 1.9 million barrels in the week to Feb. 10, with six out of seven analysts predicting a build.