Empire Properties is adding a floor of offices to The Lafayette, a 22-story condominium-hotel tower it plans at Lenoir and Salisbury streets "to meet the demand of one particular tenant," said Greg Hatem, managing partner of Empire, which agreed to pay the city $1.44 million for the half-acre development site.

He wouldn't name the tenant.

Even if the deal fell through, the office likely would attract others in the city's tightening office market.

Downtown's office vacancy rate was 6.8 percent at the end of June, down from 9.4 percent a year ago, according to Karnes Research. The office vacancy rate for the entire region dropped to 11.9 percent from 12.1 percent during the period.

The Lafayette initially was to include an 80-room hotel with 40 condominiums. It was later expanded to 125 hotel rooms, 78 condos and 14,000 square feet of offices.

The hotel would have valet and concierge services and a 200-seat restaurant, rooftop swimming pool, bar and glass elevator. Some suites will be able to accommodate 35-person cocktail parties. Condos, which go on sale in November, would cost $450,000 to $1.8 million. They range from 950 to 3,500 square feet.

The $85 million project will break ground next summer and open in 2010. It is the Raleigh developer's most ambitious.

Empire has become downtown's biggest landlord, in total properties owned, by snapping up and renovating dozens of the small buildings that line downtown's streets.

The Lafayette would be one of the company's first from-the-ground-up projects. It would compete with dozens of other hotel, condo and office projects being built or planned downtown.

Empire also is working on The L Building a few blocks northwest of The Lafayette. Construction on that 133,000-square-foot office and retail building is to begin in the spring and finish in 2009.