China's Ministry of Commerce (MOC) said Friday that the U.S.'s preliminary ruling on China-made solar cells sends "negative signals of trade protectionism" to the world.

The comment came after the U.S. Commerce Department announced Thursday that Chinese makers had dumped solar cells and panels in the United States at margins ranging from 31.14 percent to 249.96 percent.

"The result is unjustified..., and underscores the U.S.'s tendency towards trade protectionism," said MOC spokesman Shen Danyang.

He said the U.S. has refused to listen to defence and evidence presented by Chinese manufacturers when computing and assessing the dumping margins despite their active cooperation with the investigation.

"The practice is not objective and is unjustified," he said, urging the U.S. Commerce Department to right the wrongs in the upcoming probes so to avoid unfair rulings.

The preliminary result will be finally adjudged by the Commerce Department in October and the International Trade Commission in November.