WASHINGTON — The U.S. International Trade Commission voted 6-0 today to maintain a trade pact signed by the U.S. Department of Commerce and Mexico in December that suspended antidumping and countervailing duties totaling about 56% on sugar exports from Mexico and put in place quotas, minimum pricing, export licensing and other requirements, according to wire service reports.

The so-called “suspension agreements” were the result of petitions filed by a group of U.S. sugar producers March 28, 2014, charging Mexico with dumping subsidized sugar on the U.S. market that cost U.S. producers about $1 billion last year. U.S. government agencies had consistently found in favor of the U.S sugar producers and last fall imposed antidumping and countervailing duties on sugar exports to the United States from Mexico. Shipments from Mexico were record high in 2013-14 and again in 2014-15 (October-September marketing year).

Under the North American Free Trade Agreement, sugar from Mexico (and corn sweeteners from the United States to Mexico) could be exported to the United States duty-free and without volume restrictions. The December trade pact puts limits on Mexico’s sugar exports to the United States but does not impact U.S. corn sweetener shipments to Mexico.

Two U.S. cane refiners, Louis Dreyfus Commodities’ Imperial Sugar Company and AmCane Sugar L.L.C., challenged the suspension agreements in January and sought the I.T.C. review, claiming the trade pact was harmful to U.S. cane refiners. The I.T.C. vote effectively rejected the refiners’ claims.

The refiners also have asked the D.O.C. to resume its investigation into the dispute. The D.O.C. has not yet decided to continue the investigation, which was suspended in December when the suspension agreements were signed.