Major US stock indices posted mild gains Tuesday, led by troubled financial firms bailed out by the US government in the past year.

Boeing, General Electric, AT&T and United Technologies also saw their shares rise during the trading day. Boeing's gains came after rivals EADS and Northrop Grumman late Monday pulled out of a bid for a lucrative Air Force contract to build aerial refuellers.

Financials American International Group (AIG), Citigroup and mortgage companies Fannie Mae and Freddie Mac all posted strong rallies. There was no clear reason for the sudden gains.

The blue-chip Dow Jones Industrial Average added 11.86 points, or 0.11 percent, to 10,564.38. The broader Standard and Poor's 500 Index gained 1.95 points, or 0.17 percent, to 1,140.45. The technology-heavy Nasdaq Composite Index rose 8.47 points, or 0.36 percent, to 2,340.68.

The mild rally came one year after the S&P 500 hit a 12-year low at the height of the recession. The index has since climbed 69 percent.

The US currency edged up against the euro to 73.53 euro cents from 73.44 euro cents Monday. But the dollar fell against the Japanese currency to 89.99 yen from 90.25 yen.