Jan. 18 (Bloomberg) -- Cotton futures climbed to the highest closing price since May on signs of robust demand for supplies from the U.S., the worldΆs biggest exporter.

Sales of upland cotton in the week ended Jan. 10 jumped 73 percent from a week earlier, the U.S. Department of Agriculture said yesterday. In China, the worldΆs biggest consumer and importer, gross domestic product rose 7.9 percent in the fourth quarter from a year earlier, accelerating for the first time in two years, the National Bureau of Statistics said today.

“The latest U.S. export-sales report once again surprised positively,” with buyers including 19 different markets, Peter Egli, director at Chicago-based Plexus Cotton Ltd., said in an e-mailed report.

Cotton for March delivery climbed 1 percent to settle at 78.55 cents a pound at 2:30 p.m. on ICE Futures in New York, the highest closing price since May 15. Prices rose for four straight days, the longest rally since Dec. 3, and gained 3.9 percent for the week, the most since October.

“There is a decent chance for the market to explode to the upside,” Egli said.

While cotton has rallied 12 percent since the end of October, the price is 19 percent lower than a year earlier on concern that rising output in China and a drop in imports expand a global surplus. World stockpiles before this yearΆs harvest will jump 19 percent, the USDA said Jan. 11.