Chicago wheat prices trimmed earlier gains on Wednesday as more and more crops from Australia moves into the market, intensifying competition for U.S. grain in export markets. Corn dropped and soybean barely changed. The most active corn contract for December delivery trimmed 9. 25 cents, or 1.4 percent, to close at 6.45 U.S. dollars per bushel. December wheat pared 6.5 cents, or 1 percent, to 6.235 dollars per bushel. January soybean rose 0.25 cents, or 0.02 percent, to close at 12.0275 dollars per bushel. A weaker U.S. dollar and higher trade for other commodities, equity markets and metal markets, helped to support the bounce in the grain market earlier in the session. But grain prices started to give back earlier gains during mid-session, as dollar bounced off the lows and stock market also suffered a setback. A trader said that wheat suffered extra pressure on Wednesday due to shrinking export demand for U.S. wheat, as more and more Australia new crops enters world market, pulling East Asian export buyers away from the U.S.. As for corn, the corn prices lost some steam on Wednesday, as more traders expected the U.S government yield estimate could be higher, rather than lower than last month, as some private firm expected a slight increase in corn yield from last month\'s USDA estimates. Meanwhile, weather forecast showed that rains are expected in South America in next 10 days, which may improve prospects of local corn and soybeans crops. The ideas of a larger crop in South America as planting has generally been favorable is also pressuring prices.