GRAINS-CBOT wheat futures firm as corn, soybeans slip on rain forecast

(Updates headline, updates throughout to reflect US trading session, adds analyst quotes, updates prices, adds bullets, adds byline, updates dateline from PARIS/BEIJING to CHICAGO) * USDA confirms

(The article has been published through a syndicated feed. Except for the headline, the content has been published verbatim. Liability lies with original publisher.)