June 5 (Reuters) -Basis bids for corn and soybeans shipped by barge to U.S. Gulf Coast terminals were mostly weaker on Monday, with nearby values underpinned by tight spot supplies while deferred bids were pressured by slow export demand, traders said.

* Active loading of grain export vessels at the Gulf, particularly of corn exports, kept spot supplies tight in the CIF barge market, traders said. Some exporters in need of immediate supplies have had to bid up for grain needed to top off export vessels, they said.

* The U.S. Department of Agriculture (USDA) said 1,180,954 tonnes of corn were inspected for export in the week ended June 1, the fourth straight week with inspections above 1 million tonnes.

* New demand for U.S. corn and soy remained quiet as global buyers have increasingly relied on purchases from Brazil, where farmers harvested bumper crops this season. The lack of fresh export demand weighed on FOB basis offers at the Gulf.

* CIF corn barges loaded in the first half of June were bid at 70 cents over CBOT July CN3 futures, an eight-cent premium to barges loaded throughout the month. Full-month June loadings were bid 62 cents over futures, down 1 cent from late Friday.

* FOB corn export premiums were 90 cents over July CN3 futures for first-half June shipments, down 7 cents. Last-half shipments were offered 8 cents lower at 85 cents over futures.

* Soybean barge basis bids for first-half June loadings were 90 cents over CBOT July SN3 futures, down 5 cents from trades on Friday but at a 13-cent premium to full-June bids of 77 cents over futures.

* FOB soybean export premiums were flat at 97 cents over July futures for first-half June loadings and 95 cents over futures for last-half June loadings.

Reporting by Karl Plume in Chicago; Editing by Krishna Chandra Eluri

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