U.S. crude stocks rose much more than analysts expected last week, the first gain in six weeks as refineries cut output in the less-active maintenance season, the U.S. Energy Information Administration (EIA) said on Oct. 13.

Crude inventories swelled by 4.9 million barrels (MMbbl) in the week to Oct. 7, trouncing the build of 650,000 bbl that analysts had forecast. It followed five consecutive weeks of drawdowns attributed to refiners running down stocks and as imports have declined from late August.

Refinery crude runs fell by 480,000 bbl/d, EIA data showed. Refinery utilization rates fell by 2.8 percentage points.

"This report shows the effects of refinery maintenance hitting its peak for this autumn," said David Thompson, executive vice-president at energy-specialized commodities broker Powerhouse in Washington.

Oil prices were slightly higher, after a brief dip following the news. U.S. crude gained 0.5% to $50.43/bbl while Brent crude edged up 0.4% to $52.04.

Crude stocks at the Cushing, Okla., delivery hub fell by 1.3 MMbbl, EIA said.

Gasoline stocks fell by 1.9 MMbbl, compared with analysts' expectations in a Reuters poll for a 1.5 MMbbl-drop.

Distillate stockpiles, which include diesel and heating oil, fell by 3.7 MMbbl, vs. expectations for a 1.6 MMbbl drop, the EIA data showed.

"The decline in distillate fuels, of late, are starting to add up, and further drawdowns are likely as a result of the depressed refinery run rate," said John Kilduff, partner at New York energy hedge fund Again Capital.

"We remain a long way from supplies getting tight, but it is a trend worth monitoring," Kilduff said.

U.S. crude imports rose last week by 110,000 bbl/d.

Overall crude stocks excluding the U.S. Strategic Petroleum Reserve stand at 474 MMbbl, EIA said. For the first time, the overall inventories exclude about 30 MMbbl in U.S. lease stocks, an adjustment the EIA made. Those barrels are not available for commercial use, and operators often do not count them as production until the oil is transferred off the lease.