Wal-Mart Stores Inc. (WMT) on Thursday reported a 2.2 percent increase in June sales at U.S. stores open at least a year, at the low end of its already reduced forecast, as unusually cool weather hurt demand.

The world's biggest retailer said total sales for the five weeks ended July 2 reached $26.97 billion, up 9.3 percent from a year earlier.

Wal-Mart had cut its June same-store sales forecast to a range of 2 percent to 4 percent, down from its original estimate of 4 percent to 6 percent growth. The company blamed cool, wet weather for the disappointing sales.

Analysts said it was too soon to determine whether the weak June sales meant a slowdown in consumer spending, but added that if sales do not pick up with warmer weather in early July, earnings forecasts could be in jeopardy.

Wal-Mart forecast a 2 percent to 4 percent increase in July same-store sales.

The Bentonville, Ark.-based retailer said the best-selling categories in June included food paper goods, pet supplies and electronics.

Pool toys were among the weaker sales items for the month, and the company said higher gas prices also affected its customers.