US retail giant Wal-Mart has reported higher first-quarter earnings, but warned that high petrol prices could affect its customers.

The company reported net income of US$2.17bn, or 50 cents per share, for the first quarter to 30 April, compared to $1.86bn, or 42 cents per share, for the year-ago period.

Net sales were $64.8bn, an increase of 14.2% over the first quarter of fiscal 2004. Sales at the company's Wal-Mart Stores division rose 12.8% to $43.57bn, while those at Sam's Club rose 10.5% to $8.64bn. The company's international division achieved a 22.1% rise in sales to $12.55bn. Total US comparable sales for the quarter increased 6.4%.

"I am encouraged by the strengthening economy and the improving apparel environment. Although I remain concerned about the impact higher gasoline and petroleum prices will have on our customers, I am still optimistic about the balance of the year," said president and CEO Lee Scott.

Besides its US operations, Wal-Mart has stores in Argentina, Brazil, Canada, China, Germany, Mexico, Puerto Rico, South Korea and the United Kingdom. Wal-Mart also owns a 37.8% interest in Japan's Seiyu.