Wal-Mart has reported solidly higher profits for its financial second quarter as US sales rebounded.

Wal-Mart, the world's biggest retailer, said net profit was $3.8 billion for the three months to July 31, a rise of 5.7% from the same period in 2010.

The company said earnings were $1.09 per share excluding once-off items, slightly higher than estimated by analysts.

Sales at Wal-Mart US discount stores open at least a year fell 0.9% from the first quarter, marking the ninth straight quarterly decline. But the company said sales improved each month during the quarter.

'I'm encouraged by the sales improvement in our Wal-Mart US stores,' Wal-Mart chief executive Mike Duke said in a statement. He said it was Wal-Mart's best quarterly performance since the third quarter of last year.

Wal-Mart has been battling a slump in its domestic market amid a struggling economy.

International sales for the company's main Wal-Mart discount chain leapt more than 16% in the quarter, to $30.1 billion, compared with a modest 0.4% rise in the US.