U.S. trade officials confirmed that the World Trade Organization has issued a preliminary ruling in a case against Chinese export restrictions on certain industrial raw materials but said they could not comment yet on the decision.

"We can confirm that a WTO panel issued its confidential interim report in the dispute brought by the United States against China challenging China's export restraints on various industrial raw materials used as inputs in the manufacture of steel, aluminum and chemical products," said Nefeterius McPherson, a spokeswoman for the U.S. Trade Representative's office.

"Under WTO rules, this interim report is confidential and we cannot comment on its contents at this time," she said.

"The report will be made public when it is circulated to WTO members. We currently expect the final report to be circulated sometime in late spring or early summer of 2011." (Reuters)