(Rewrites throughout with U.S. market open, adds quote, updates

prices, changes dateline from LONDON/CANBERRA)

By Karl Plume

CHICAGO, Aug 15 (Reuters) -

U.S. corn and soybean futures rose on Friday on

short-covering ahead of the weekend and a closely-followed crop

tour set to begin surveying fields across the Midwest next week.

Chicago Board of Trade wheat also edged higher after

concerns about big global supplies dragged the market to

contract lows earlier this week.

Corn and wheat futures were on pace for weekly declines for

a fourth straight week as abundant supplies weighed on both

markets, while soybeans were set to post a weekly gain for the

first time in four weeks after a smaller-than-expected U.S. crop

forecast from the U.S. Department of Agriculture this week.

"The risk is, at the moment, to the upside. The funds are

short grains and oilseeds, and we've got that crop tour that

starts on Monday," said Craig Turner, a commodity broker at

StoneX.

"If you're short and you're up and you've got a winning

position, I don't know why you wouldn't take a little profit

here heading into the weekend with the crop tour coming up."

CBOT December corn was up 6-3/4 cents at $4.04 a

bushel by 12:20 p.m. CDT (1720 GMT), while November soybeans

added 14-1/2 cents to $10.43 a bushel. CBOT September

wheat was 1-1/2 cents higher at $5.05 a bushel.

The Pro Farmer Midwest crop tour will estimate corn yields

and gauge soybean production potential across seven states next

week before issuing its crop outlook next Friday.

Grain traders will be monitoring findings after the USDA

earlier this week projected a record-smashing U.S.

corn harvest

and smaller soybean crop.

A recent uptick in corn export demand, sparked by low

prices, has limited further pressure in corn futures.

A stronger-than-expected July U.S.

soybean crush

, released at mid-session by the National Oilseed Processors

Association, offered soybean futures an additional lift.

(Additional reporting by Nigel Hunt and Peter Hobson; Editing by

Rashmi Aich, Christina Fincher and Paul Simao)