(Reuters) - U.S. crude oil inventories fell last week, but an unexpected build in gasoline stocks and weak demand for the motor fuel offset market optimism over the crude drawdown, the Energy Information Administration said on Wednesday.
Crude inventories USOILC=ECI fell 1.7 million barrels in the week to June 9, compared with analysts' expectations for a decrease of 2.7 million barrels, as imports USOICI=ECI fell 481,000 barrels per day.
Refinery crude runs USOICR=ECI also rose 29,000 bpd and utilization rates USOIRU=ECI rose 0.3 percentage point to 94.4 percent of total capacity.
However, gasoline stocks USOILG=ECI rose 2.1 million barrels, compared with analysts' expectations in a Reuters poll for a 457,000-barrel drop.
Gasoline inventories currently sit at 242.4 million barrels, or 9 percent, above the five-year average of 223 million barrels, according to EIA data.
Gasoline demand over the past four weeks in the United States, the world's top consumer of the motor fuel, was 9.53 million bpd, off 1.2 percent from a year ago.
"This is very unusual for this time of the year, when gasoline demand is supposed to pick up," said Carsten Fritsch, oil analyst at Commerzbank AG in Frankfurt, Germany.
High inventories have weighed on the futures' market's crack spreads, a measure of refining margins, throughout spring when refiners produce more gasoline for driving season. But inventories usually start drawing down in the peak demand summer driving season.
After the data, the gasoline spread to crude RBc1-CLc1 slumped about 4 percent to its lowest since May 4.
Reformulated blendstock gasoline futures 1RBc1 dropped 3.4 percent to $1.449 a gallon as of 10:59 a.m. EDT (1459 GMT). U.S. crude futures CLc1, meanwhile, were down 3.4 percent to $44.92 a barrel, the lowest intraday level since May 5.
"The build in gasoline stocks was a result of a further decline in gasoline demand, which marks a very subdued start into the summer driving season," said Fritsch.
Crude stocks at the Cushing, Oklahoma, delivery hub USOICC=ECI fell by 1.2 million barrels, EIA said.
Oil inventories have remained high several months into a deal by OPEC producers with non-member nations to reduce supply by 1.8 million bpd.
The Organisation of the Petroleum Exporting Countries agreed to extend that deal that began in January through March 2018, but ongoing growth in U.S. production, along with exemptions for non-members Nigeria and Libya, have offset those cuts to some extent.
In a report on Wednesday, the International Energy Agency said rising U.S. output will contribute to supply growth exceeding demand growth in 2018.
U.S. crude production has been steadily growing and last week rose to 9.33 million bpd, up 12,000 from the previous week, the EIA said.
Reporting By David Gaffen; additional reporting by Scott DiSavino; Editing by Marguerita Choy