At the closing bell, the Dow Jones Industrial Average rose 30.05 (0.18 percent) to 16,951.51, a new high.
The S&P 500 advanced 3.56 (0.18 percent) to 1,963.04, while the tech-rich Nasdaq Composite Index gained 8.71 (0.20 percent) to 4,368.04
General Electric's campaign to buy Alstom's energy assets for $16.8 billion appeared within striking reach after the French government endorsed the deal.
As part of the deal, France will take a dominant 20 percent stake in Alstom by buying buy two-thirds of the shares owned by French group Bouygues.
GE's offer was taken over a rival bid by Germany's Siemens and Japan's Mitsubishi Heavy Industries.
Dow component GE rose 0.2 percent to $26.98.
Meanwhile, US oil prices moved to a fresh nine-month high of $107.26 a barrel as the battle against Sunni extremists showed no signs of abating. Grand Ayatollah Ali al-Sistani, Iraq's leading Shiite cleric, called on people to unite to fight the insurgents.