Sept 13 (Reuters) -Basis bids for corn and soybeans shipped by barge to the U.S. Gulf Coast were firmer on Friday on rising freight costs and as shippers anticipated a restart of export loading following terminal closures caused by Hurricane Francine, traders said.

* Soybean basis values have firmed this week as barge freight costs climbed while demand for new-crop supplies has improved, particularly from top importer China. Worries about dry late-season weather in the United States and an arid start to Brazil's season also kept a floor under prices.

* Spot barge freight costs in the Midwest have surged by 50 to 125 percentage points of tariff in the past week on rising harvest-season demand and low water problems on the lower Mississippi River that are restricting tonnage per barge.

* Rains from the now-downgraded Hurricane Francine are expected to lift river levels, but not by much. The waterway at Memphis is still forecast to fall to within about 3.5 feet of its all-time low later this month, according to National Water Prediction Service data.

* Shippers are loading less grain in barges to limit drafts in the low water conditions. Barge lines are also restricting the number of barges per tow to navigate the narrower shipping channel.

* CIF corn barges loaded in September were bid 2 cents higher at 70 cents over Chicago Board of Trade December CZ24 futures.

* October export premiums were unquoted on tight near-term export loading capacity following recent rain delays and the hurricane, traders said.

* FOB Gulf export premiums for corn shipped in November were unchanged at 110 cents over CBOT December futures.

* CIF September soy barges were bid 7 cents higher at 68 cents over CBOT November soybean SX24 futures.

* FOB November soy export premiums were unchanged at 117 cents over futures.

Reporting by Karl Plume in Chicago
Editing by Marguerita Choy

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