Still, investors were anxious to see if earnings would be enough to move stocks higher, given the recent strong run.
The S&P 500, which is up 7 percent since the start of the year, rose to within a few points 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.
Aluminum company Alcoa Inc rose 2.1 percent to $14.69 shares. The Dow component kicks off the first-quarter reporting period with results after the bell. Analysts expect the company to post a first-quarter profit of 10 cents per share, a big improvement from the loss of 59 cents last year.
The earnings are going to be very good on both cost and revenues, and if you're ever going to celebrate, it would be right now. If (the market) doesn't, it means it's already priced in, said Jim Awad, managing director at Zephyr Management in New York.
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 stressed that Athens had not yet asked that the plan to be activated.
The Dow Jones industrial average <.DJI> was up 23.35 points, or 0.21 percent, at 11,020.70. The Standard & Poor's 500 Index <.SPX> added 3 points, or 0.25 percent, at 1,197.37. The Nasdaq Composite Index <.IXIC> gained 3.33 points, or 0.14 percent, at 2,457.38.
Mirant Corp led a new batch of mergers and acquisition activity after the big U.S. power producer agreed to take over rival RRI Energy Inc , while Palm Inc , the smartphone maker, is reportedly looking to sell itself.
Mirant shares surged 18.8 percent to $12.675, and RRI Energy gained 13.9 percent to $4.50. Palm shares jumped 16.5 percent to $6.
(Additional reporting by Chuck Mikolajczak; editing by Jeffrey Benkoe)