SINGAPORE/PARIS - Chicago wheat fell on Thursday as traders monitored ongoing diplomatic discussions over sea access for Ukrainian grain shipments, while corn and soybeans eased ahead of a closely watched U.S. crop report.

Wider financial markets were also subdued as investors awaited the outcome of a European Central Bank meeting expected to herald its first interest rates in a decade.

The most-active wheat contract on the Chicago Board of Trade (CBOT) was down 1.9% at $10.54-3/4 a bushel by 1056 GMT. The wheat market has been buffeted by varying statements from political leaders on a possible Black Sea corridor for Ukrainian shipments blocked since Russia's invasion.

Turkish efforts to negotiate safe passage for grain stuck in Ukrainian ports met resistance, as Ukraine said Russia was imposing unreasonable conditions and the Kremlin said free shipment depended on an end to sanctions. "Ukraine's export access remains an issue but there seems to have been little progress," said Tobin Gorey, director of agricultural strategy at the Commonwealth Bank of Australia.

Wheat markets have also been weighed down by improving weather for U.S. and European crops in the run-up to summer harvesting.

Grain traders were adjusting positions ahead of the U.S. Department of Agriculture's (USDA) monthly world crop forecasts on Friday, which will give an update on U.S. prospects and a further assessment of the impact of the war in Ukraine. Before that, the market will get an update on demand from weekly U.S. exports sales figures at 1230 GMT. CBOT soybeans were down 0.4% at $17.32-1/2 a bushel, after nearing on Wednesday a decade high hit in February. CBOT corn lost 0.7% to $7.59-1/4 a bushel following a one-week peak on Wednesday.

Firm U.S. cash markets, stronger crude oil prices and forecasts pointing to drier weather in the U.S. Midwest have supported soybeans and corn this week.

A sharp drop in palm oil futures on Thursday weighed on soyoil, a byproduct of soybeans.

(Reporting by Naveen Thukral in Singapore and Gus Trompiz in Paris; Editing by Rashmi Aich and Aditya Soni)