General Motors said Thursday its net income more than tripled in the first quarter thanks to stronger sales and sales of assets, including its stake in former auto-parts arm Delphi Automotive.

GM said net income rose to US$3.2 billion from $865 million. Operating profit increased to $2 billion from $1.7 billion. Revenue rose 15 per cent to $36.2 billion from $31.5 billion.

GM North America generated net income of $2.9 billion, compared to $1.2 billion last year. But, it lost money in Europe, to $390 million, from $477 million in the first quarter of 2010.

“We are on plan,” Dan Akerson, GM’s CEO and chairman and chief executive, 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.”

GM expressed optimism about the rest of 2011, saying it expects operating profit to rise in the remaining quarters of 2011. The gain builds on the $4.7 billion GM made in 2010, its most profitable year since 1999.