US retail giant Wal-Mart has upped its first quarter earnings guidance on the back of strong sales for the month of March.

US comparable store sales during the five-week March period were driven by a good performance from its three largest units – grocery, health and wellness and entertainment – the company said.

“Customers continued to turn to Wal-Mart for price leadership throughout the store, and they continued to see a better shopping experience,” said Eduardo Castro-Wright, Wal-Mart Stores US president and chief executive officer. “In addition, we benefited from better integration of merchandising, operations and marketing.”

Internationally, Wal-Mart reported a strong performance from the UK, Canada, Brazil and China.

“We are pleased with the overall performance of our International markets,” said Mike Duke, vice chairman responsible for Wal-Mart International.

Wal-Mart said it expected April sales in the US to rise by 1-3%.

“We are raising our guidance for earnings per share from continuing operations for the first quarter of fiscal year 2009 to a range of $0.74 to $0.76. This is an increase from the previous earnings guidance of $0.70 to $0.74 per share from continuing operations,” said Tom Schoewe, executive vice president and chief financial officer.