company man

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A man whose primary allegiance is to his employer.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun idiomatic A male employee who has a great—and often, in the view of others, an excessive—commitment to serving the interests of the organization which employs him.
• noun idiomatic A spy or other operative of an intelligence service, especially the U. S. Central Intelligence Agency.
• noun idiomatic A male homosexual.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an employee whose first loyalty is to the company rather than to fellow workers