General Motors reported Thursday that first-quarter profit more than tripled from the year-ago period to $3.15 billion on strong demand for its new fuel-efficient vehicles. Revenue surged 15 % to $36.2 billion in the January-March period, up $4.7 billion from a year earlier and beating market expectations. Earnings per share were 95 cents, topping the average analyst forecast of 93 cents. The biggest US automaker said it was solidly on the profit track after a massive government rescue that allowed it to emerge from bankruptcy reorganization in 2009. \"We are on plan,\" GM chairman and chief executive Dan Akerson said in a statement. \"GM has delivered five consecutive profitable quarters, thanks to strong customer demand for our new fuel-efficient vehicles and a competitive cost structure that allows us to leverage our strong brands around the world and focus on driving profitable automotive growth.\"