Sept 30 (Reuters) -Basis bids for corn and soybeans shipped by barge to the Gulf Coast were mixed on Monday after slumping late last week as improved river shipping conditions offered exporters greater access to supplies, traders said.

* Nearby export premiums at the Gulf were also lower.

* Recent rains across the central United States, including from Hurricane Helene, recharged water levels in the Mississippi River and its tributaries. Low water had plagued the rivers for weeks, limiting barge drafts and reducing tow sizes.

* The Mississippi River at Memphis, a key chokepoint for grain flowing to Gulf export terminals, is expected to rise by another four feet by the end of the week, according to a forecast from the National Water Prediction Service.

* Barge lines began easing restrictions on drafts on Friday, allowing shippers to move more grain per vessel, traders said. Freight rates, which had propped up CIF values for weeks, were expected to ease with the improved shipping conditions.

* CIF September soy barge bids were a penny higher at 76 cents over Chicago Board of Trade November soybean SX24 futures after tumbling by 15 cents on Friday. October soybean barges were also bid 1 cent higher at 76 cents over futures.

* FOB soy export premiums for the first half of November fell to 125 cents over futures and last-half November offers fell to 120 cents over futures, each down 5 cents.

* CIF corn barges loaded in September were bid 2 cents lower at 72 cents over CBOT December CZ24 futures. October barge bids fell 2 cents to 76 cents over futures.

* FOB Gulf corn export basis offers were 112 cents over futures for first-half November shipment and 109 cents over for last-half, both down 3 cents.

Reporting by Karl Plume in Chicago; Editing by Shailesh Kuber

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