U.S. stocks advanced on Monday after European leaders agreed to an emergency aid plan for Greece and ahead of quarterly results from Alcoa Inc, which marks the unofficial start to earnings season.

While many are anticipating a solid quarter for corporate profits, some investors are also waiting to see if the results would be enough to move stocks higher, given Wall Street's recent strong run.

The S&P 500, which is up 7 percent since the start of the year, rose to within one point of the 1,200 level, seen as an area of technical resistance. The Dow, meanwhile, traded above 11,000 after briefly topping that level on Friday for the first time since September 2008.

Dow component Alcoa is scheduled to report its first-quarter results after the market closes, kicking off the earnings season. Analysts expect the aluminum company to swing to a first-quarter profit from a year ago, and the stock rose 2.2 percent to $14.71.

Helping to relieve worries about sovereign debt that could have repercussions through other parts of the continent, euro zone ministers signed off on a 30 billion euro ($40 billion) rescue package for Greece on Sunday. But they stressed that Athens had not yet asked that the plan to be activated.

There's some relief, since it's certain that something will be done to help Greece, but the markets may swing until all of the details are figured out, said Marc Pado, U.S. market strategist at Cantor Fitzgerald in San Francisco.

The Dow Jones industrial average <.DJI> was up 14.66 points, or 0.13 percent, at 11,012.01. The Standard & Poor's 500 Index <.SPX> was up 3.25 points, or 0.27 percent, at 1,197.62. The Nasdaq Composite Index <.IXIC> was up 5.97 points, or 0.24 percent, at 2,460.02.

The Dow's top boost was Caterpillar Inc , which gained 2.4 percent to $66.84 after Robert W. Baird analysts upgraded the stock to outperform from neutral on an improving macroeconomic landscape.

Other companies expected to report this week include Intel Corp , Google Inc , General Electric Co and Bank of America Corp .

Intel and Bank of America are really going to set the tone for the season, and good results at those (companies) will really help the Nasdaq and S&P, respectively, Pado said. Strong results could lift the S&P index to 1,260, he said.

UBS AG posted its highest pretax profit since the start of the credit crisis, sending U.S.-listed shares of the company up 3.8 percent to $17.15.

Power producer Mirant Corp agreed to take over rival RRI Energy Inc , while Palm Inc
, the smartphone maker, is reportedly looking to sell itself.

Mirant shares shot up 19 percent to $12.75, and RRI Energy gained 14 percent to $4.52. Palm was the most active stock on the Nasdaq, and the shares jumped 19 percent to $6.12.

First-quarter earnings for S&P 500 companies are expected to rise 36.8 percent from a year ago, according to data from Thomson Reuters.

(Editing by Padraic Cassidy)