An employee of the high-security communications section at the U.S. Embassy in Beijing has been transferred out of the country after Chinese intelligence agents asked him to spy for them, diplomatic sources said Tuesday.

The abortive bid by Chinese intelligence to penetrate the communications section, the embassy's most heavily secured department, was the first espionage-related incident reported in U.S.-China relations since late last year.The diplomatic sources, who refused to be identified further, said the American employee reported the overture to his superiors and that no classified information was compromised.

U.S. Embassy spokesmen refused official comment on the incident, which the sources said occurred in September.

"This is on a close-hold basis," a U.S. official said. "There is nothing we can say."

According to the sources, the unidentified American worked in the communications section, which handles all embassy message traffic, including top-secret intelligence and diplomatic cables.