* Prices mixed after USDA's monthly crop report

* U.S. government raises forecasts for U.S. exports, world stocks

* Weak China export data weighs on commodities markets

NEW YORK, March 10 (Reuters) - Cotton futures edged up in mixed trading on Monday, buoyed by a U.S. government forecast for lower ending 2013/14 inventories in the United States, the world's top exporter, even as world supplies are projected to climb.

The benchmark May cotton contract on ICE Futures U.S. clawed back gains to close up 0.29 cent, or 0.3 percent, at 91.56 cents a lb.

Prices earlier turned lower after rallying as much 1.1 percent to 92.60 cents a lb immediately after the U.S. Agriculture Department's (USDA) monthly supply-demand report.

The Thomson Reuters/Core Commodity CRB index, a benchmark for global commodities markets, was under pressure from weak export data in China, the world's top consumer of many raw materials and second-largest economy.

The U.S. government forecast a bullish picture for the United States, the world's top exporter, lowering its outlook for stocks to 2.8 million 480-lb bales on higher exports.

Even so, prices turned down from session highs as the USDA raised its forecast for world inventories, expected to hit a record 96.75 million bales by end-July.

The contract swung as low as 90.68 cents a lb.

"It's a case of buy the rumor, sell the fact," said Louis Rose of Risk Analytics LLC in Memphis, Tennessee.

Second-month prices hit six-month highs above 93 cents a lb last week ahead of the report that was widely expected to project higher exports and lower stocks for the United States.

Open interest totaled 173,303 lots on Friday, down slightly from the previous session but up 12,425 lots from the previous week, ICE data showed on Monday.

The rise in open interest alongside rallying prices was taken as evidence of new buying.

"This is a bull market, but the speculators don't want to jump on here and push it higher," Rose said.

Cotton futures have rallied 8.5 percent this year as tightening U.S. supplies have offset expectations that world stocks will hit a record and that Beijing will overhaul in 2014 a stockpiling program that has driven voracious demand for foreign fiber.

Exchange inventories ticked up to 259,581 bales on Friday, the most in almost eight months, according to the most recent ICE data compiled by Reuters. (Reporting by Chris Prentice; Editing by Chizu Nomiyama )