CHICAGO, June 10 (Reuters) - Basis bids for corn and soybeans shipped by barge to U.S. Gulf Coast export terminals turned higher on Wednesday, as supplies on river markets continue to tighten as farmers' selling interest chilled, traders said.

• Farmers have been slower to sell their stored crops recently, as futures have turned lower and corn prices have hovered near multi-month lows.

• Chicago Board of Trade corn futures ended mixed on Wednesday, with the most-active July contract hovering above a life-of-contract low set this week, while generally benign U.S. crop weather capped rallies, traders said.

• Meanwhile, U.S. soybean futures markets have dropped into oversold territory, analysts said, amid heavy selling pressure. CBOT's most-active soybean contract Sv1 has ended lower in 15 of the last 20 sessions.

• Export demand for U.S. crops has slowed, market analysts said, as buyers are now looking to cheaper, newly harvested supplies from South America entering the global market.

• Argentina's Rosario grain exchange (BCR) on Wednesday raised its production forecast for the 2025/26 soybean crop to 51.5 million metric tons and for the 2026/27 wheat crop to 20 million tons, it said in its monthly report.

• Traders spent much of the day adjusting their positions ahead of Thursday's monthly supply-and-demand report from the U.S. Department of Agriculture. Analysts surveyed by Reuters, on average, expected the USDA to trim its U.S. wheat production forecasts and raise its estimates of corn and soybean crops in Brazil and Argentina.

• CIF corn barges loaded in June were bid at 77 cents over Chicago Board of Trade July CN26 futures, up 2 cents from bids on Tuesday. July corn barges traded at 88 cents over futures and were bid 87 cents over futures late on Wednesday.

• FOB export premiums for Gulf corn vessels loaded in July held steady at around 103 cents over futures.

• For soybeans, CIF barges loaded in June were bid 5 cents higher at 75 cents over CBOT July SN26 futures. July loadings traded steady at 88 cents over futures.

• FOB export premiums for soybean vessels loaded at the Gulf in July were unchanged at around 109 cents over futures.

For displays of CIF basis, click on the codes in brackets:

U.S. CIF Gulf soybeans GRYM

U.S. CIF Gulf corn GRYN

U.S. CIF Gulf SRW wheat GRYO

U.S. CIF Gulf HRW wheat GRYP

For displays of FOB basis, please click on the following codes in brackets:

U.S. FOB Gulf corn GRZC

U.S. FOB Gulf soybeans GRZD

U.S. FOB Gulf SRW wheat GRZE

U.S. FOB Gulf HRW wheat GRZF

LINKS

Corn prices page: cpurl://apps.cp./cms/?pageid=corn-cash-market

Wheat prices page: cpurl://apps.cp./cms/?pageid=wheat-cash-market

U.S. barge freight BG/US

U.S. export sales estimates USDA/EST

U.S. grain export summary GRA/U

Brazil soybean export prices SYBS

Brazil corn export prices SYBX

Argentina grain prices GRA/ARG

Russia grain prices GRA/RU