BEIJING, May 19 (Reuters) - U.S. wheat extended gains on Thursday, after India unexpectedly banned wheat exports last week, while Russia-Ukraine war kept underpinning global grains markets.

The most-active wheat contract on the Chicago Board of Trade (CBOT) was up 0.89% at $12.41-3/4 a bushel.

CBOT wheat had climbed more than 8% over the past two days, following India's wheat ban and reports showing bad condition of U.S. winter crop.

CBOT soybeans edged up 0.95% to $16.78-1/2 bushel, extending gains, while corn rose 0.48% to $7.85-1/4 a bushel.

Wheat remained firm despite reports of a record size crop of Russian wheat and estimates of more exports from the country, and the prospect of Ukraine shipping out more of the grains stuck there with the United Nations' help.

U.N. Secretary-General Antonio Guterres said on Wednesday that he was in "intense contact" with Russia, Ukraine, Turkey, the United States and the European Union in an effort to restore Ukrainian grain export as a global food crisis worsens.

Russia was seen to export more wheat in the new marketing season due to a large harvest and stockpile, the IKAR consultancy said on Wednesday.

India said on Tuesday it would allow overseas wheat shipments awaiting customs clearance, introducing some leeway for overseas sales after it banned exports of the staple on Saturday.

Commodity funds were net sellers of Chicago Board of Trade corn, wheat, soybean and soyoil futures contracts on Wednesday, and net buyers of soymeal, traders said.

Bearish factors started to weigh on corn and soybean markets, though worries over tightening supplies in the global agriculture sector continued to support prices.

Agribusiness consultancy Agroconsult cut its forecast of Brazil's second corn crop to 87.6 million tonnes in the 2021/2022 cycle, down from a previous 92.2 million-tonne forecast.

High gasoline prices could also encourage more blending of corn-based ethanol, and higher use of edible oils to make fuel, but in the meanwhile, near record high prices of vegetable oils and concerns over global food crisis would push government to limit the use of such biofuel.

Asian stocks eked out their fourth session of gains, but the recent rally lost momentum as nagging doubts about inflation and the drag from rate hikes overshadowed bits and pieces of good news about the global growth outlook. (Reporting by Hallie Gu and Dominique Patton; Editing by Rashmi Aich)