Recasts; updates prices, adds quotes, changes byline, changes dateline from previous PARIS/SINGAPORE

By Julie Ingwersen

CHICAGO, March 7 (Reuters) - Chicago Board of Trade corn futures rose for a third straight session on Friday as news of exemptions for Mexico and Canada to most U.S. tariffs allowed grain prices to stabilize after a plunge early this week.

Soybean futures were flat to narrowly mixed while wheat futures drifted lower but stayed inside of Thursday's trading range.

A drop in the dollar =USD lent support, making U.S. grains cheaper overseas.

As of 12:54 p.m. CST (1854 GMT), CBOT May corn CK25 was up 6-1/4 cents at $4.70-1/4 per bushel. May soybeans SK25 were unchanged at $10.27-1/4 a bushel and CBOT May wheat WK25 was down 1-1/2 cents at $5.52-1/2 a bushel.

The ongoing saga with U.S. tariffs remained the focus of the market. On Thursday, U.S. President Donald Trump suspended the tariffs he imposed days earlier on most goods from Canada and Mexico, the latest twist in a fluctuating trade policy.

"It's been a wild week," said Ted Seifried, chief market strategist for Zaner Ag Hedge. "We are just really exhausted, taking a little bit of a breather," Seifried said of Friday's market moved.

Trump imposed 25% tariffs on imports from Mexico and Canada on Tuesday and fresh duties on Chinese goods, fuelling worries that an expanding trade war would threaten demand for U.S. agricultural exports.

Mexico was the largest buyer of American corn and wheat in 2024 and the No. 2 destination for U.S. soybeans after China, so averting trade barriers supported grain futures, Seifried said.

However, the U.S. is still in a trade war with top global soy buyer China. Additionally, reciprocal trade barriers and other duties are expected to take effect in the following weeks.

China bought 13.61 million metric tons of soybeans in January and February, up 4.4% from the year-earlier period, according to customs data issued on Friday.

Traders expect soy flows to slow in March after some buyers brought forward shipments in anticipation of tit-for-tat tariffs. China on Tuesday responded to the latest U.S. levies with tariffs on a range of U.S. farm goods including soybeans.

Market players are looking ahead to the U.S. Department of Agriculture's next monthly supply/demand report on March 11. The report will consider trade policies in place when the forecasts for grains and soybeans are issued, an agency official said on Thursday.

(Reporting by Julie Ingwersenl; additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Cynthia Osterman)

((Julie.ingwersen@thomsonreuters.com; 1-313-484-5283; Reuters Messaging: julie.ingwersen.thomsonreuters.com@reuters.net))