Updates throughout with market moves, adds byline and bullets, updates headline, changes dateline from PARIS/BEIJING

By P.J. Huffstutter

CHICAGO, June 26 (Reuters) - Chicago Board of Trade corn and soybean futures eased on Friday, as forecasts of hot U.S. weather raised concerns about corn crop conditions, and traders watched for signs of renewed Chinese soy demand.

Trade was choppy in CBOT corn futures the day after a technical reversal driven by a growing sense among traders that funds may have been too aggressive in shedding long positions, market analysts said.

However, a hot turn to Midwest weather starting this weekend did bring some support for Chicago grains, which had previously shown little reaction to a heatwave in Western Europe threatening corn crops there.

The National Weather Service forecast that temperatures could reach 100 degrees Fahrenheit this weekend as far north as the upper Midwest and as far east as the Carolinas. Hotter-than-normal weather is expected from the Plains to the Atlantic Coast through July 4.

Part of the concern is the timing of a heatwave — and more importantly, whether extreme heat will continue through July, when corn crops in the Midwest typically go through pollination, market analysts said.

CBOT wheat futures kept slumping on Friday, with the most-active contract Wv1 on track to end lower for the fifth session in six, on supply pressures from Northern Hemisphere harvests.

"Wheat just continues to be unimpressive," said Ted Seifried, chief market strategist for Zaner Ag Hedge.

The most-active soybean contract Sv1 on the Chicago Board of Trade was down 0.09% at $11.56 a bushel at 12:18 p.m. CDT (1718 GMT).

Crude oil prices fell by about 3% on Friday, on course for steep weekly losses as supply concerns eased with more oil tankers exiting the Strait of Hormuz. O/R

The decline in energy prices weighed on soybeans and corn, both of which are used as feedstocks for biofuels. CBOT corn Cv1 slipped 0.06% to $4.42-3/4 per bushel. CBOT wheat Wv1 fell 2.08% to $5.89 per bushel.

Traders also spent some of the day getting positions ready for the U.S. Department of Agriculture acreage and stocks reports on June 30, among the most widely followed data in grain markets.

Still, traders seemed to show less interest in making big position moves going into the weekend, in part from a lack of relevant news, said Karl Setzer, partner at advisory firm Consus Ag Consulting. "Next Tuesday’s acreage and stocks reports will give the market fresh data to sift through, even if numbers are little changed from estimates," he said.

USDA is expected to report June 1 wheat stocks were up 9.2% from a year earlier, a Reuters poll of analysts showed.

USDA is also expected to report that June 1 corn stocks were up 16.5% from a year earlier and that farmers planted about 95 million acres of corn this spring, Reuters polls showed. The agency is expected to report that U.S. soybean stocks on June 1 were up about 3.8% from a year earlier and that farmers planted about 85.4 million acres of soybeans this spring, analysts said.