Oil prices fell on Wednesday after weekly data showed a sharp increase in U.S. crude inventories, while investors remained cautious about Europe’s ability to agree on a plan to address its debt crisis.

U.S. crude oil stocks rose sharply last week, the Energy Information Administration (EIA) said, much more than analyst expectations. Refined product stocks fell more than expected, however, despite refining rates rising.

“The report is a mixed bag of extremes. The sizable crude build, despite the increase in refinery utilization, is definitely challenged by the drawdown in distillates and the significant rise in year-on-year demand,” said John Kilduff, partner at hedge fund Again Capital LLC.

On a four-week average, U.S. distillate fuel demand rose last week to the highest level since the week to Feb. 20 2009, the EIA’s report showed.

North Sea Forties crude differentials fell for the first time this week on signs of increasing supplies, adding to Wednesday’s bearish supply snapshot. Maintenance-limited production had recently been a supportive factor for oil, especially for Brent crude futures.

ICE Brent crude for December fell $1.12 to $109.80 a barrel by 1:44 p.m. (1744 GMT), having traded from $108.76 to $111.78.

U.S. December crude fell $1.60 to $91.57 a barrel, after peaking at $93.92.

The more supportive EIA inventory data for refined products helped limit losses for U.S. heating oil and gasoline futures to a lower percentage than for crude.

Brent’s premium to its U.S. counterpart moved back above $18 a barrel, as investors and analysts noted the rise in crude stocks at Cushing, Oklahoma, the delivery hub for the light sweet crude contract on the New York Mercantile Exchange, along with the overall rise in crude inventories.

Most markets were in flux as eurozone heads of state met after EU officials said the leaders were unlikely to attach hard numbers to their crisis response because of ongoing negotiations on the size of banks’ losses on Greek bonds.