U.S. stocks leapt, posting the biggest single-day gain in a month, as euro-zone leaders worked toward a new pact to stem Europe's sovereign-debt crisis and a strong start to the holiday shopping season boosted the retail sector.

The Dow Jones Industrial Average jumped 291.23 points Monday, or 2.6%, to 11523.01, snapping a four-day losing streak and erasing more than half of last week's steep losses. Last week's swoon of 4.8% marked the worst Thanksgiving-week performance since markets began closing in observance of the holiday in 1942.

The Standard & Poor's 500-stock index climbed 33.88 points, or 2.9%, to 1192.55, snapping a seven-day losing streak as all but six of the broad index's components gained. Materials, energy and technology stocks posted the largest gains. The technology-oriented Nasdaq Composite rose 85.83 points, or 3.5%, to 2527.34. All three stock indexes posted their biggest point gains since Oct. 27. For the Nasdaq, it was the biggest percentage gain since Aug. 23.

European markets finished with a rally and the Stoxx Europe 600 soared 3.8% after news that euro-zone leaders were negotiating another agreement to contain the sovereign-debt crisis. A new pact, including measures to curb excessive debt by making budget discipline legally binding, could persuade the European Central Bank to take more action to halt the selloff in debt markets. Meanwhile, the International Monetary Fund denied a report it was in bailout talks with heavily indebted Italy.

"We've seen 2011 be a 'risk-on, risk-off' environment," said Stephen Wood, chief market strategist at Russell Investments. "There's going to be some kind of resolution [in Europe or] a solution will be forced on Europe by the markets."

Sales on Black Friday, the day after Thanksgiving, rose 6.6% from a year ago, and sales for the four days starting on Thanksgiving increased 16%, according to ShopperTrak. Meanwhile, the National Retail Federation said shoppers spent 9.1% more on Black Friday than they did last year. The overall retail sector benefited, pushing the SPDR S&P Retail exchange-traded fund to a gain of $1.67, or 3.4%, to $50.17.

Amazon.com rallied 11.75, or 6.4%, to 194.15, after the online retailer said it sold four times more Kindle devices on Black Friday than it did last year.

Consumer-electronics retailers also showed strength, with Best Buy rising 86 cents, or 3.4%, to 26.49. Separately, Apple rose 12.55, or 3.5%, to 375.12.

"To have such growth in an economically uncertain environment was encouraging to investors," said Lawrence Creatura, portfolio manager at Federated Investors. "[But] the shopping season has many days left and it's not clear whether exceptionally low prices, increased hours and broader availability didn't just borrow sales from future weeks."

Crude-oil prices advanced for the third session in four, rising $1.44 per barrel, or 1.5%, to $98.21. Gold gained for the first time in three days, rising $25.30 per troy ounce, or 1.5%, to $1710.80.

Asian bourses posted gains as well. Japan's Nikkei Stock Average rose 1.6% and Hong Kong's Hang Seng Index advanced 2%. The U.S. dollar fell against the euro, but rose against the yen.

Demand for U.S. Treasury bills rose slightly, driving yield on the 10-year note down to 1.958%, the fourth drop in five days. Bond prices move inversely to their yields.

In economic news, sales of homes rose slightly in October, but demand remained weak in historical terms. Sales increased 1.3% to a seasonally adjusted annual rate of 307,000, from a downwardly revised pace of 303,000 in September, according to the Commerce Department.

Elsewhere, Commercial Metals Co. surged 2.72, or 24%, to 14.17. Billionaire investor Carl Icahn's Icahn Enterprises offered to acquire the scrap-metal processor in a bid valuing the company at roughly $1.73 billion, or a 31% premium to the stock's closing price Friday.

Oil stocks jumped following reports that the European Union is considering banning imports from Iran, the latest escalation in tensions over the country's nuclear program. Alpha Natural Resources leapt 1.48, or 7.9%, to 20.29; Consol Energy gained 2.06, or 5.8%, to 37.35, and Marathon Oil added 1.32, or 5.4%, to 25.98.

Madison Square Garden jumped 2.61, or 10%, to 28.37, after NBA owners and union officials reached an agreement Saturday to end the basketball league's lockout.

UnitedHealth Group affirmed its 2011 earnings forecast but provided a 2012 outlook that was slightly below expectations. The stock rose 1.36, or 3.1%, to 45.03.

-By Brendan Conway, Dow Jones Newswires; (212) 416-2670; brendan.conway@dowjones.com