* Improved crop weather pressure corn and soybeans

* Corn poised for weekly gains, soybeans down in week

* Traders looking ahead to next week's USDA crop S&D data

(Rewrites throughout, adds quote, updates prices, changes byline, changes dateline from SINGAPORE/PARIS)

CHICAGO, July 7 (Reuters) - U.S. corn and soybean futures fell on Friday as recent welcome rains across the Midwest farm belt, and forecasts for more next week, aided crops that had been suffering under an early season drought.

Soybeans, which notched a four-month high to start the week, were on pace for a 1.5% weekly decline, but corn was poised for its first weekly gain in three weeks after hitting the lowest point in 2-1/2 years at midweek.

Grain traders are monitoring shifts in weather as more U.S. corn enters its critical pollination stage. Two-thirds of corn and 60% of soybeans were affected by drought as of July 4, according to the U.S. Department of Agriculture.

"Rain makes grain and we've had some pretty good rains. There are some questions as to how much has fallen and how much good it has done, but I would expect that the (crop condition) ratings on Monday should be steady to up," said Mark Gold, managing partner at Top Third Ag Marketing.

Normal to above-normal precipitation was forecast for the central and southern Midwest in the six to 15 day period, and the northwest corner of the region was seen remaining largely dry, according to Commodity Weather Group.

Chicago Board of Trade December corn was down 9-1/2 cents at $4.97 a bushel at 12:21 p.m. CDT (1721 GMT) while November soybeans fell 19-1/2 cents to $13.20 a bushel.

CBOT September wheat dropped 6-1/2 cents to $6.51-1/2 a bushel, nearly unchanged for the week.

Weekly USDA corn export data showed sales in line with trade expectations last week, while wheat sales and new-crop soybean sales topped estimates.

Additionally, the USDA on Friday confirmed that Mexico purchased 180,000 metric tons of old- and new-crop U.S. corn.

Traders are awaiting a monthly USDA supply-and-demand report on Wednesday, with cuts to U.S. corn and soybean yield estimates possible.

(Additional reporting by Naveen Thukral in Singapore and Sybille de La Hamaide in Paris; Editing by Rashmi Aich, Maju Samuel and David Evans)