Sanshan Du and Yu Qin

After an almost month-long trial, former General Motors engineer Shanshan Du and her husband, Yu Qin, were convicted Sunday of stealing hybrid vehicle trade secrets from the automaker. Qin was convicted on seven counts, while Du was convicted of three trade-secret counts but acquitted of wire fraud charges.

Prosecutors said Qin used the data in attempts to either get employment with or form partnerships with GM's Chinese competitors, including Chery Automobile Co. GM claimed in the trial that the secrets were worth more than $40 million. Defense lawyers said the data wasn't secret, wasn't stolen and was "useless for other companies."

"These defendants stole trade secrets, which General Motors spent many years and millions of dollars to develop, to give an unfair advantage to a foreign competitor," US Attorney Barbara McQuade said. "We hope that this prosecution will send a message that stealing proprietary information from an employer or competitor is a serious crime."

Du worked for GM from 2000 until her resignation in 2005. Prosecutors argued that Du and her husband had formed Millennium Technology International through which they had hoped to sell the stolen information. Lawyers said 16,262 stolen files were found on Du's computer.

Sentencing is scheduled for February. The couple face maximum sentences of 10 years on each trade secret count and fines of as much $250,000.