Oil advanced after an Israeli airstrike killed a leader of Hamas’s militant wing in the Gaza Strip, bolstering concern that unrest in the Middle East will intensify curbing supplies.

Futures rose as much as 1.4 percent after the attack, which killed Ahmed al-Jabari and another man, according to Ashraf al- Qedra, a spokesman for the Hamas-run Health Ministry. The strike follows the firing of about 115 rockets from Gaza into Israel this week.

Countries in the Middle East and North Africa were responsible for 36 percent of global oil production and held 52 percent of proved reserves in 2011, according to BP Plc (BP/)’s Statistical Review of World Energy.

Oil fell earlier as U.S. retail sales declined for the first time in four months in October. U.S. retail sales decreased 0.3 percent in October, according to the Commerce Department in Washington. The median forecast of 83 economists called for a drop of 0.2 percent.

Crude oil for December delivery advanced 61 cents, or 0.7 percent, to $85.99 a barrel at 11:12 a.m. on the New York Mercantile Exchange. Prices are down 13 percent this year.

Brent oil for December settlement, which expires tomorrow, rose $1.18, or 1.1 percent, to $109.44 a barrel on the London- based ICE Futures Europe exchange. The more actively traded January contract gained $1.02 to $108.36.