DETROIT — General Motors’ second-quarter profit more than doubled to a post-bankruptcy record $2.87 billion on a strong performance in the U.S., where the company saw sales fall after it cut low-profit sales to rental car companies. It raised its earnings guidance for the year.

Its shares rose almost 3 percent.

The company earned a record $3.6 billion pretax profit in North America, made $500 million on its joint venture in China and even eked out a $137 million profit in Europe, its first five years. But profits were nearly halved in international operations due to struggles in the Middle East.

Yet GM sees the good times continuing in the U.S., its main profit center, even though sales fell 4.4 percent during the first half of the year and its market share dropped a full percentage point to 16.6 percent, the lowest level since at least 1980.

The Detroit automaker said it earned $1.81 per share from April through June.