Oil pared gains after U.S. inventories unexpectedly increased last week and gasoline supplies climbed more than twice as much as forecast.

Stockpiles of crude rose 843,000 in the week ended Dec. 7, the Energy Department said today. Inventories were forecast to decrease 2.5 million barrels.

Oil inventories increased to 372.6 million barrels in the first gain in four weeks, the Energy Department reported. Gasoline stockpiles jumped to 217.1 million, the most since April 6.

Oil rallied as much as 1.6 percent earlier as the International Energy Agency increased its demand forecast and on speculation the Federal Reserve will expand stimulus measures.

Global oil consumption in the fourth quarter will average 90.5 million barrels a day, about 435,000 barrels, or 0.5 percent, more than previously forecast, the Paris-based IEA said in a monthly report today. Demand will expand by 865,000 barrels a day in 2013 to 90.5 million, adding 110,000 barrels to a previous outlook.

The Organization of Petroleum Exporting Countries maintained its quota at 30 million barrels a day for a second time this year at a meeting today in Vienna after the group’s members judged prices to be sufficiently high.

Crude oil for January delivery advanced to $86.70 a barrel on the New York Mercantile Exchange after rising to $87.16 earlier. Oil traded at $86.80 a barrel before release of the inventory report.

Brent for January settlement on the London-based ICE Futures Europe exchange gained $1.47, or 1.4 percent, to $109.48 a barrel.