The head of a security-guard company that serviced city housing projects pleaded guilty yesterday to stealing $1.2 million in sales taxes, and received a sentence that will keep him behind bars for as little as 2 1/3 years, despite his not having repaid a penny.

Abdur Rashid Salaam, 51, had collected the taxes for the companies he owned, but then pocketed the money instead of turning it over to the state.

Manhattan Supreme Court Justice Michael Obus had promised Salaam the light sentence over the objections of prosecutors, who had cited the seriousness of the thefts.

Salaam could have been sentenced to a maximum of 8 1/3 years in prison.

Salaam used the money to support his families in Teaneck, NJ, and Georgia, according to prosecutors.