U.S. District Judge Leonie M. Brinkema also ordered Tai Shen Kuo, 58, to forfeit $40,000 for conspiracy to deliver national defense information to China. Kuo pleaded guilty May 13.

Kuo, a naturalized citizen, began spying for China in March 2007. He obtained national defense information from Gregg W. Bergersen -- a weapons systems policy analyst at the Defense Security Cooperation Agency, an agency within the Department of Defense in Arlington. The information mostly involved U.S. military sales to Taiwan and U.S. military communications security classified as secret.

Kuo gave Bergersen gifts, cash payments, dinners and trips to such places as Las Vegas.

"Kuo also led Bergersen to believe that he would make Bergersen a part owner or an employee of a company selling U.S. defense technology to Taiwan after Bergersen's retirement from government service," the Justice Department said in a release.

Bergersen was sentenced July 11 to 57 months in prison and three years supervised release.

Co-conspirator Yu Xin Kang was sentenced Aug. 1 to 18 months in prison for aiding and abetting an unregistered agent of a foreign government.