CHICAGO, Sept 1 (Reuters) - U.S. corn futures fell about 2% on Wednesday, with the benchmark December contract hitting a seven-week low as worries about shipping delays from the U.S. Gulf Coast triggered a round of long liquidation, analysts said.

Soybean futures hit a two-month low and wheat followed the weaker trend. Commodity funds hold net long positions in Chicago Board of Trade corn and soybean futures, leaving both markets vulnerable to bouts of long liquidation.

As of 1:03 p.m. CDT (1803 GMT), CBOT December corn was down 10-1/2 cents at $5.23-3/4 per bushel, after dipping to $5.18-1/4, the contract's lowest since July 12.

CBOT November soybeans were down 15-1/2 cents at $12.77 a bushel after hitting $12.70, its lowest since June 28. December wheat was down 7-1/4 cents at $7.15 a bushel.

Traders continued to gauge damage around U.S. Gulf Coast export terminals following Hurricane Ida. The storm damaged two grain export elevators owned by global grain trader Cargill Inc in Louisiana, and rival shipper CHS Inc warned on Monday its grain facility may lack power for weeks after the storm tore through the busiest U.S. grains port.

Corn futures fell for a third day on fears that the problems could back up U.S. grain exports as the fall harvest approaches.

"This week's Ida-related selling led to chart-related selling in the grain and oilseed sector as momentum remains to the downside," said Arlan Suderman, chief commodities economist for StoneX.

Wheat futures followed corn and soy lower, backing away from 8-1/2-month highs set in August.

"The fundamentals of the northern hemisphere (crops) are generally known," consultancy Agritel said in a note. "It is mainly technical considerations that are currently dominating."

Sovecon said on Tuesday it had cut its forecast for Russia's 2021 wheat crop to 75.4 million tonnes from 76.2 million, with the consultancy citing low spring wheat yields.

Meanwhile, forecasts pointed to moderate weather for Midwest corn and soy crops, including rain in some dry northwestern zones, as attention turns to harvesting that is getting under way. (Reporting by Julie Ingwersen in Chicago; additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Subhranshu Sahu and Jonathan Oatis)