* Light buying keeps market range bound since July 11 tumble

* Trade looks forward to yield figure in next USDA report

NEW YORK, July 23 (Reuters) - Cotton futures edged higher for a second straight session on Wednesday on extended buying by mills, while traders looked for more distinctive signs of supply and demand after nearly two weeks of range-bound trading.

The benchmark December cotton contract on ICE Futures U.S. closed up 0.17 cent, or 0.3 percent, at 68.08 cents a lb, on a modest volume of less than 7,500 lots, Thomson Reuters data showed.

The contract has traded in a tight range of not more than a cent since hitting a more than two-year low July 11, after a U.S. government crop report that sharply boosted supply prospects for world cotton supply.

The U.S. Department of Agriculture will issue its next monthly report on cotton on Aug 12 and expectations are that it will reveal more bearish numbers, said traders.

"But one reason the market's holding up is that the report will also contain a new figure for expected yield for the 2014/2015 crop, and that's something that could sway the market a little," said Keith Brown, cotton broker at Keith Brown and Co. in Moultrie, Georgia.

"Also, some small patches of buying by the mills have helped."

While price losses have been minimal over the past fortnight, traders said it was tough to find bullish factors as beneficial rains sprinkled on Texas and Georgia, the two largest cotton producing states.

And while some harsh weather earlier in the year will delay crop development, some farmers are still bracing for a bumper yield.

A weekly USDA report released on Monday after the market's close showed the majority of the U.S. cotton crop was in good or excellent condition, a jump from the previous year. (Reporting by Barani Krishnan; Editing by Diane Craft)