WASHINGTON (Dow Jones)--The U.S. Commerce Department announced a preliminary decision Thursday to impose antidumping duties against imports of magnesia carbon brick from China and Mexico.

Commerce determined that the brick, used in furnaces primarily for the production of iron and steel, is being sold below fair value.

Chinese firms will receive a preliminary duty rate of between 132.74% and 349%, while the rate for Mexican companies was set at 54.73%.

Imports of certain magnesia carbon bricks from China rose 3.8% by volume from 2006 to 2008, with a value of $50.8 million that year. Imports from Mexico rose 7.7% to $7.7 million over that period.

The Commerce department is investigating more than 20 countervailing and antidumping cases involving Chinese companies, as U.S. producers are increasingly seeking relief from what they claim are unfair trade practices. China, complaining of protectionism, has challenged some of the duties at the World Trade Organization.

Commerce launched both antidumping and countervailing investigations into the bricks in August, following a complaint by Resco Products Inc.

As a result of the preliminary determination, the U.S. Customs and Border Protection will collect a cash deposit or bond. Commerce plans to make a final decision in July, and then the U.S. International Trade Commission must find that the imports harm U.S. producers before the duties can go into effect.

-By Tom Barkley, Dow Jones Newswires; 202-862-9275; tom.barkley@dowjones.com

MARCH 4, 2010, 1:31 P.M. ET

Source: online.wsj.com