A vendor pours grains of rice into a bag at a rice sale-agent at the Voi market, 20 km south of Hanoi April 16, 2008. REUTERS/Kham

NEW YORK (Reuters) - Wal-Mart Stores Inc’s Sam’s Club warehouse division said on Wednesday that it is limiting sales of Jasmine, Basmati and long grain white rices “due to recent supply and demand trends.”

The news comes a day after Costco Wholesale Corp, the largest U.S. warehouse club operator, said it had seen increased demand for items like rice and flour as customers, worried about global food shortages, stock up.

Sam’s Club said it is limiting sales of the rices to four bags per customer per visit, and it is working with its suppliers to ensure the products remain in stock.

Sam’s Club, the No. 2 U.S. warehouse club operator, said it is not limiting sales of flour or cooking oil at this time.

Costco said some of its stores had put limits on sales of items such as rice and flour, but it was trying to modify those restrictions to meet customer demand.

Food costs have soared worldwide, spurred by increased demand in emerging markets like China and India, competition with biofuels, high oil prices and market speculation.

Rice prices in the United States and around the world have more than doubled in the last year, and U.S. rice futures rose to a fresh all-time high Wednesday on worries about supply shortages.

Trade bans have been put in place by India, the world’s second largest rice exporter in 2007, and Vietnam, the third biggest, in the hopes of cooling domestic prices of the staple. Thailand is the largest rice exporter.