Crude oil rose, capping the biggest monthly gain since May 2009, after U.S. second-quarter gross domestic product and weekly jobless claims beat economists’ estimates in signs that demand may improve.

Oil jumped to a seven-week high on a government report that the world’s largest economy grew at a 1.7 percent annual rate in the second quarter. The price also gained as the decline in jobless claims indicated that companies are cutting back on firings and on an unexpected drop in gasoline stockpiles.

“The market is still viewed as economics-led,” said Tom Bentz, a broker with BNP Paribas Commodity Futures Inc. “People are looking ahead to when the economy is going to recover and demand is going to cause drawdowns in some of the inventories.”

Oil for November delivery gained $2.11, or 2.7 percent, to settle at $79.97 a barrel on the New York Mercantile Exchange. The price ranged from $77.55 to $80.18, the highest price since Aug. 11. Futures climbed 11 percent in September and 5.7 percent in the third quarter.

The revised GDP figure exceeded the 1.6 percent median forecast of economists surveyed by Bloomberg News. Growth slowed from 3.7 percent in the first quarter.

U.S. initial jobless claims decreased by 16,000 to 453,000 in the week ended Sept. 25, lower than the 460,000 median forecast of 47 economists surveyed by Bloomberg News, Labor Department figures showed today in Washington. Unemployment has hovered around 10 percent.

“When the data’s good, it really spurs crude on,” said Matt Smith, a commodities analyst for Summit Energy in Louisville, Kentucky. “Crude’s still being latched onto as a proxy for risk appetite.”

U.S. Business Activity

Business activity in the U.S. also accelerated unexpectedly this month, according to the Institute for Supply Management- Chicago Inc. The group said its business barometer climbed to 60.4 in September, exceeding the highest estimate of economists surveyed by Bloomberg News.

“People are starting to realize that economically, the country is moving forward,” said Carl Larry, president of Oil Outlooks & Opinions LLC in Houston. “It’s all about demand. Whether it’s small or large, it’s still coming, it’s still growing, and that’s the key here.”

Gasoline Demand, Inventories

Gasoline consumption jumped 6.1 percent last week to 9.38 million barrels a day, the biggest one-week increase since Feb. 19, according to the Energy Department.

Stockpiles of the motor fuel fell 3.47 million barrels to 222.6 million. They were forecast to increase by 350,000 barrels, according to a Bloomberg News survey. Crude inventories also slipped 475,000 barrels to 357.9 million.

“The initial factor for this move was U.S. oil storage data, although I don’t see U.S. demand picking up enough for prices to get much higher,” said Gerrit Zambo, a trader at Bayerische Landesbank in Munich.

Gasoline for October delivery gained 4.93 cents, or 2.5 percent, to expire at $2.0448 a gallon on the Nymex, the highest level since Aug. 10. The more-active November futures rose 5.32 cents, or 2.7 percent, to $2.0361.

Oil output from OPEC, supplier of 40 percent of the world’s crude, fell to an eight-month low in September, led by Iraq, where a pipeline disruption curtailed shipments, a Bloomberg News survey showed today.

OPEC Output

Production slipped 145,000 barrels, or 0.5 percent, to an average 29.055 million barrels a day, the lowest level since January, according to the survey. Output by members with quotas, all except Iraq, dropped 95,000 barrels to 26.76 million, 1.92 million above their target.

The Organization of Petroleum Exporting Countries is unlikely to change output levels when it meets next month, Kuwait’s oil minister said. Sheikh Ahmad al-Abdullah al-Sabah said in Hanoi yesterday that he is “happy” with current prices. OPEC’s next ministerial meeting is Oct. 14 in Vienna.

The government of Ecuador, the smallest OPEC oil producer, called for international help after what it called a “coup attempt” today by members of its security forces. The opposition is behind the attempt to take down the government, according to a statement on the president’s website.

Ecuador pumped 465,000 barrels a day of crude this month, or 1.6 percent of OPEC’s total, a Bloomberg News survey showed today. OPEC’s current president is Wilson Pastor, Ecuador’s minister of non-renewable natural resources.

Ecuador exported 200,000 barrels a day of oil to the U.S. in July, or 2 percent of total imports, based on the most recent monthly data from the Energy Department.

Brent crude for November settlement gained $1.54, or 1.9 percent, to $82.31 on the ICE Futures Europe exchange in London, the highest closing price since Aug. 3.

Oil volume in electronic trading on the Nymex was 776,736 contracts as of 3:46 p.m. in New York. Volume totaled 794,709 contracts yesterday, 22 percent above the average of the past three months and the highest level in more than two weeks. Open interest was 1.34 million contracts.