The U.S. stocks pared some of the early gains on Tuesday as corporate merger activities and growing expectations of a Greece bailout package boosted the market.

Energy and material shares were among best performers as commodities prices rebounded. Crude oil prices rose back to near 80 U.S. dollars a barrel on the New York Mercantile Exchange.

The U.S. stocks opened higher as upbeat economic data from Japan and mounting expectations on a Greece bailout boosted global markets.

Investors embraced the news that Japan's unemployment rate dropped for the second straight month in January and household spending grew, which are positive signs for recovery in the world' s second-largest economy.

Merger activity lifted stocks for a second day. CF Industries repeated a buyout offer for fertilizer maker Terra Industries, which last month agreed to be sold to Norway's Yara for 4.1 billion U.S. dollars.

Tech-heavy Nasdaq was boosted after wireless chips maker Qualcomm Inc. announced a stock buy-back plan worth 3 billion dollars and raised its dividend by 12 percent.

Carmakers were in the spotlight on Tuesday as they reported auto sales for February. A report from General Motors showed its U. S. sales rose 11.5 percent in February over the period a year ago.

The U.S. stocks advanced on Monday, with major averages touching their highest levels in more than a month, as Greece bailout hopes, merging news and better-than-expected consumer spending data lifted sentiment.

The Dow Jones rose 2.19, or 0.02 percent, to 10,405.98. The Standard & Poor's 500 index gained 2.60, or 0.23 percent, to 1,118. 31 and the Nasdaq was up 7.22, or 0.332 percent, to 2,280.79.