Sept 27 (Reuters) -Basis bids for soybeans shipped by barge to the Gulf Coast tumbled on Friday as rising river levels were poised to improve shipping conditions after low water had impeded grain movement for weeks, traders said.

* Sharply higher futures prices also weighed on soy bids.

* Heavy rains from Hurricane Helene over the Ohio River valley were forecast to recharge drought-depleted Midwest rivers after weeks of low water had limited grain barge movement.

* At Memphis, the depth of the Mississippi River was expected to rise by almost 15 feet from a near-record low set on Tuesday due to flows from the tributary Ohio River, according to a forecast from the National Water Prediction Service.

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

* CIF September soy barge bids fell 15 cents to 75 cents over Chicago Board of Trade November soybean SX24 futures. October soybean barges were bid 5 cents lower at 75 cents over futures.

* Export premiums for soy remained elevated as loading capacity was limited following recent weather delays.

* FOB soy export premiums for the first half of November were unchanged at 130 cents over futures. Last-half November offers were steady at 125 cents over futures.

* CIF corn barges loaded in September were bid 6 cents higher at 74 cents over CBOT December CZ24 futures. October barge bids rose 3 cents to 78 cents over futures.

* FOB Gulf corn export basis offers were 115 cents over futures for first-half November shipment and 112 cents over for last-half, both steady.

Reporting by Karl Plume in Chicago; Editing by Shounak Dasgupta

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