Oct. 19--By the time the FBI came knocking on their doors in July 2003, engineers Lan Lee and Yuefei Ge were already caught in the cross hairs of a government investigation into whether they were stealing technology from their Silicon Valley employers to establish a rival company backed by China.

More than six years later, the story of their suspected theft of superfast computer chip plans is about to emerge from the shadows. In the second trial of its kind in the nation, the engineers are set to face economic espionage charges in federal court in San Jose. Jury selection is scheduled to begin Tuesday.

Lee, 44, and Ge, 36, are among just a handful of defendants to face federal charges under a section of the 13-year-old Economic Espionage Act, designed to prevent the illegal transfer of technology to foreign governments. While a number of defendants have pleaded guilty and been sentenced, only one other has gone to trial -- a former Boeing Co. and Rockwell International engineer convicted this summer in Santa Ana federal court for passing critical information on the space program to China.

For Silicon Valley, where companies have worried for years about their prized secrets being leaked to China and other countries, such a trial is a window into the complexities of protecting product information in a place with ties to every corner of the global economy.

The trial also is fraught with pitfalls for prosecutors and the defense, both of whom

are entering largely uncharted territory of how jurors will assess whether trade secrets were illegally stolen for a foreign government, China.

"It's challenging for prosecutors in these cases to demonstrate a clear intent to benefit the foreign government," said Scott Frewing, a former federal prosecutor who advises companies on protecting trade secrets. "And the challenge for the defense is that in China, every part of the economy is dominated by the government, so the links are more obvious."

Lee and Ge have pleaded not guilty to the charges that include theft of trade secrets and violations of the espionage law. If convicted, they face 10 years or more in prison, although most convicted on economic espionage charges in recent years have received much lower sentences. Ed Swanson, Ge's lawyer, declined to comment. Tom Nolan, Lee's attorney, did not return calls seeking comment.

In court papers, defense lawyers suggested Lee and Ge had no intention of doing anything to illegally benefit China. Lee, a U.S.