CHICAGO (Dow Jones)--Chicago Board of Trade corn ended slightly lower Friday, pressured by favorable planting weather forecasts and declining crude oil prices.

May corn lost 1 1/2 cents for the week, and ended 2 1/2 cents lower Friday at $3.45 3/4 per bushel. July corn was down 2 1/4 cents to $3.57 1/4.

The market was slightly weaker throughout the session following what traders saw as a mixed U.S. Department of Agriculture report. The report doesn't change the market's bearish fundamental picture, analysts said.

"The market goes back to trading weather's influence on Monday," said Tim Hannagan, analyst for PFG Best.

As of Friday, the outlook was bearish, with warm and relatively dry weather expected in the Midwest through next week, allowing for fieldwork and planting. Early planting is getting off to a good start, analysts said.

Crude oil, which was firm Friday morning, retreated later in the day, weighing on corn.

John Kleist, broker/analyst with Allendale, said that while forecasts were bearish, losses were limited by uncertainty ahead of the weekend, and the potential forecasts could change by Monday.

Prices fell despite gains in soybeans, and an analyst said there was buying of soy and selling of corn. Funds sold an estimated 5,000 contracts.

Kleist said there was spread trading, with buying of soybeans and selling of corn, based on the weather outlook. Good planting weather early in the season will boost corn acres and could limit the number of farmers who opt for soybeans because they won't have to worry about sloppy corn planting, analysts say.

The USDA supply and demand report issued what some saw as a friendly domestic carryout estimate of 1.899 billion bushels Friday morning. That was slightly below trade estimates, but still "comfortable," according to analysts. Meanwhile, world ending stocks climbed, affirming the bearish outlook.

CBOT oats ended lower Friday. May oats slipped 2 1/2 cents to $2.15 per bushel and July oats closed down 4 cents to $2.21 1/2.

Ethanol futures were steady to slightly lower. May ethanol closed flat at $1.537 per gallon and June ethanol settled down $0.006 to $1.554.

-By Ian Berry, Dow Jones Newswires; 312-341-5778;