Imports of high-tech steel from China are unfairly subsidized by the Chinese government, U.S. trade officials said in a preliminary ruling, potentially escalating a spat over trade of the specialty steel product.

The U.S. Commerce Department estimated a subsidy rate of 49.15 percent on imports of grain-oriented electrical steel from Baoshan Iron & Steel Co and other Chinese exporters.

In January, the United States took action at the World Trade Organization, complaining that China used tariffs to effectively block imports of U.S. steel despite a WTO ruling in the United States’ favor. It is used in the cores of high-efficiency transformers, electric motors and generators.

In 2013, imports of grain-oriented electrical steel from China were valued at an estimated $5.4 million. The complaint was lodged by AK Steel Holding Corp and Allegheny Technologies Inc..

In other preliminary rulings, the U.S. Commerce Department found China was unfairly subsidizing imports of food additive monosodium glutamate, following a complaint by Ajinomoto North America Inc. It rejected a similar gripe about Indonesia.

The U.S. department found that imports of ferrosilicon from Venezuela were being sold in the United States below market prices and set a preliminary dumping margin of 27.27 percent, but said this was not the case with imports from Russia.

That complaint was made by Globe Specialty Metals Inc and CC Metals and Alloys LLC.

The Commerce Department and the International Trade Commission have yet to issue final rulings in the cases. (Reuters)