The former boss of a US company's Chinese subsidiary Tuesday pleaded guilty to illegally supplying material to Pakistan for use in a nuclear reactor and is now cooperating with US investigators.

US prosecutors said that Xun Wang faces up to five years in jail and a fine of $250,000 for conspiring to violate US law by sending the high-quality paint coatings to Pakistan via China after being refused a US export license.

No sentencing date was set.

"At the end of last year, the Chinese subsidiary of a US company pleaded guilty to illegally exporting high-performance coatings for use in a Pakistani nuclear reactor," said US Attorney Ronald Machen in the capital Washington.

"Today we are pleased to see the former managing director of that subsidiary accept responsibility for her role in the crime.

"We also welcome the defendant's decision to cooperate with the government in our ongoing investigation of this blatant violation of US export laws."

Wang, 51, the ex-managing director of PPG Paints Trading (Shanghai) Co. Ltd, pleaded guilty to conspiring to export and ship high-performance epoxy coatings to the Chashma 2 Nuclear Power Plant in Pakistan (Chashma II).

The facility is run by the Pakistan Atomic Energy Commission (PAEC), the science and technology organization responsible for Pakistan's nuclear program, including the development and operation of atomic power plants.

In November 1998, following Pakistan's first successful detonation of a nuclear device, the US Commerce Department added the PAEC to the list of banned end-users of such goods under American export regulations.

Wang has already paid a separate $200,000 penalty in connection with her case.

According to her plea documents, in January 2006, PPG Industries sought an export license for the shipments of coatings to Chashma II. In June 2006, the US Department of Commerce denied the application.

But Wang and her co-conspirators then agreed upon an illegal scheme to export and ship PPG Industries' high-performance epoxy coatings from the United States to Chashma II, via a third-party distributor in China.