WESTBORO, Mass. (AP) _ The president of Staples Inc. has resigned after being charged with assaulting a co-worker with whom he was accused of having an affair.

The office supply store company said Monday that an internal investigation found that Martin Hanaka had a ``non-business relationship'' with secretary Cheryl Gordon. The company prohibits managers from associating with subordinates.

Gordon, once a secretary for Hanaka, also resigned after being found in violation of the policy, a spokeswoman said.

Hanaka could not immediately be reached for comment. A man who answered the phone at his Westboro house said he was playing golf.

Earlier this month, Hanaka, 48, was charged with assaulting Gordon.

Hanaka, who is married, told police that Gordon concocted a bogus extramarital affair so she could blackmail him for a promotion, according to police reports. Although he denied that the affair happened, he told police he gave her more than $10,000 since July to keep quiet.

Hanaka was arrested on a domestic assault charge Feb. 9, two days after he allegedly went to Gordon's Framingham apartment and argued with her. He pleaded innocent to the charge.

Hanaka, who is also chief operating officer, will remain as a full-time consultant for six months. He will report to Thomas Stemberg, founder and chief executive officer.