CHICAGO, Dec 19 (Reuters) -Spot basis bids for soybeans and corn delivered by barge to U.S. Gulf Coast terminals were generally steady on Thursday, though bids for deferred month loadings were mixed, traders said.

* Chicago Board of Trade soybean futures Sv1 rebounded on technical buying on Thursday, after plunging to a four-year low a day earlier, while corn Cv1 was buffeted by weakness in wheat and a stronger dollar.

* The U.S. Department of Agriculture on Thursday confirmed private sales of 227,200 metric tons of soybeans to "unknown" destinations, of which 152,200 tons are for delivery during the 2024/25 marketing year and 75,000 tons are for delivery during the 2025/26 marketing year.

* Empty barge freight rates turned higher on the Illinois and Ohio Rivers amid delay and demand issues, barge sources said, while heavily loaded barges traveling along the Upper Mississippi River are expected to need to lighten their loads starting next week due to water level concerns.

* At the Gulf, CIF soybean barges loaded in December traded at 95 cents over Chicago Board of Trade January SF25 soybean futures, while those loaded in January traded at 93 cents over futures, traders said.

* CIF soybean Gulf barges loaded in December were bid at 92 cents over Chicago Board of Trade January SF25 futures, steady from Wednesday.

* FOB export premiums for January soybean shipments were 1 cent lower at about 107 cents over futures.

* For corn, CIF barges loaded in January-February-March traded at 73 cents over CBOT March corn futures CH25, and barges loaded in April-May traded at 61 cents over May corn futures CK25.

* CIF corn barges loaded in December were bid steady at 69 cents over CBOT March corn CH25 futures.

* FOB offers for corn shipped from the Gulf in January eased by 1 cent at 86 cents over CBOT March futures.

Reporting By P.J. Huffstutter in Chicago; Editing by Shreya Biswas

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