CHICAGO: US wheat futures leaped to a five-month high on Tuesday on hopes for increased export sales, while corn and soyabeans consolidated amid lingering uncertainty about the size of upcoming harvests in the Midwest.

Weakness in the US dollar helped support gains in wheat prices, traders said, because a soft dollar makes American farm products look more attractive to importers.

Traders said talk of Chinese purchases of US wheat triggered speculative buying, although no deals were confirmed.

Wheat supply forecasts have tightened in exporting nations like Argentina and France due to unfavorable weather.

"A lot of the major exporters didn't have great wheat crops," said Jim Gerlach, president of Indiana-based brokerage A/C Trading.

The most-active Chicago Board of Trade wheat futures contract gained 11-3/4 cents to close at $5.64 per bushel and reached its highest price since April 1. Funds bought an estimated 11,000 contracts, traders said.

Most-active soyabeans closed 1-1/4 cents higher at $9.54-3/4 a bushel, easing back from Monday's two-year peak of $9.66-3/4.

Most-active corn settled up 1/4 cent at $3.58. It earlier touched a one-week low of $3.51 as it eased back from Monday's five-month high of $3.64-1/4.

Dryness in the US Midwest grain belt, along with the impact of a mid-August windstorm in Iowa, have led traders and analysts to scale back previous projections for massive autumn corn and soyabean harvests.

Uncertainty about the size of the harvests should continue to underpin prices for both crops, Gerlach said.-Reuters