* Potential for harvest delays sparks short-covering
* Corn near 5-year low, soybeans near 4-1/2 year low
* Markets under pressure from huge U.S. harvest (Updates U.S. market to close)
By Michael Hirtzer
CHICAGO, Oct 1 (Reuters) - U.S. corn and soybeans edged higher on Wednesday as investors covered short positions after prices fell to multiyear lows earlier in the session and as rains stalled record harvests in the Midwestern crop belt.
Wheat futures also rose, stabilizing after reaching four-year low last week. The gains followed the U.S. Agriculture Department's largely bearish quarterly stocks and small grains summaries that were released on Tuesday.
"There's no trigger (for higher prices) other than you have the crop report behind you," said analyst Roy Huckabay of the Linn Group Chicago brokerage. "I don't see anything coming in the Oct. 10 (USDA) report that's not going to be bearish, but when you're down so hard, there's fewer sellers."
Most-active Chicago Board of Trade December corn finished 1/2 cent higher at $3.21-1/4 per bushel after falling to $3.18-1/4, the lowest level since September 2009.
CBOT November soybeans were up 3-1/2 cents at $9.16-3/4, rebounding from a session low of $9.04, the lowest since Feb. 4, 2010.
Substantial rain fell in the western Corn Belt on Tuesday while more showers were likely this week and the following six to 10 days, delaying field work, the Commodity Weather Group said in a note to clients.
"Corn is trading near its daily high on talk of rains slowing harvest progress over the next few days in the face of a stronger dollar and weaker outside markets," said analyst Brad Metzger of Futures International in Chicago.
Plentiful global grain stockpiles and a rising dollar that made U.S. supplies less competitive in international markets continued to anchor corn, soybean and wheat prices. Each commodity capped large quarterly and monthly declines during the previous session.
CBOT wheat was up 1-1/4 cents at $4.79 per bushel, rebounding from the contract's worst monthly loss since 2011.
Wheat rose despite U.S. shippers missing out on a tender to sell grain to top importer Egypt, whose main buying agency instead purchased 120,000 tonnes from France. (Additional reporting by Julie Ingwersen in Chicago, Michael Hogan in Hamburg and Naveen Thukral in Singapore; Editing by Keiron Henderson, Lisa Von Ahn and Jeffrey Benkoe)