(Recasts, updates with U.S. trading, adds new analyst quote, changes byline/dateline; pvs PARIS/SINGAPORE)
CHICAGO, March 2 (Reuters) - Chicago Board of Trade wheat futures sank 4.0 percent on Friday, setting back from a six-day rally that pushed prices to their highest in 7-1/2 months, traders said.
"This has just been a fantastic week of gains," said Bill Gentry, a broker at Risk Management Commodities. "The funds are taking a little bit of profit ahead of the weekend."
The sharp decline in wheat weighed on the corn market, which sagged after peaking at its highest since August.
Soybean futures were weaker after hitting their highest since July 2016. The soy market remained underpinned by signs of good export demand and expectations that dry weather will cut the size of the Argentine harvest and further boost the desirability of U.S. exports to overseas buyers.
K.C. hard red winter wheat futures were also lower, but held up better than CBOT wheat contracts, due to forecasts for below-normal moisture levels over the next few weeks in the U.S. Plains.
At 11:07 a.m. CST (1707 GMT), CBOT May soft red winter wheat futures were down 20-1/2 cents at $4.95 a bushel. K.C. hard red winter wheat for May delivery was down 16-3/4 cents at $5.26-3/4 a bushel.
For the week, CBOT wheat has risen 6.6 percent and K.C. wheat has risen 8.8 percent.
CBOT May soybean futures were 1-1/4 cents lower at $10.66-3/4. Soybean futures have risen 1.8 percent this week, their fourth straight of week of gains.
The U.S. Agriculture Department on Friday morning said that private exporters reported the sale of 198,000 tonnes of soybeans to China, the second day in a row a sale to the world's biggest buyer of the oilseed has been announced.
Dry weather in Argentina, the world's biggest soyoil and soymeal supplier, remains a critical market factor.
Crop conditions for drought-battered corn and soybeans in Argentina worsened this week and ratings among the top three provinces are now on average about 23 percentage points lower than a month ago.
The poor conditions prompted the Buenos Aires Grain Exchange to cut its forecast for the country's soybean crop on Thursday to 44 million tonnes, from its previous estimate of 47 million. The corn estimate was unchanged at 37 million tonnes.
CBOT May corn futures were 2 cents lower at $3.84-1/4 a bushel. Corn has risen 4.9 percent this week. (Additional Reporting by Naveen Thukral in Singapore and Sybille de La Hamaide in Paris Editing by David Goodman and Rosalba O'Brien)