Larry Silverstein revealed his plans today for a 912-foot-high, mixed-use tower at 99 Church Street just to the west of the 792-foot-high Woolworth Building at 233 Broadway.

The tower will have 175 rooms in a hotel in its base that will be operated by Four Seasons Hotels and Resorts and 143 condominium apartments, some of which will have as much as 6,500 square feet. The hotel will be on the lower 22 floors in the 80-story building.

The design of the project by Robert A. M. Stern calls for the very slender tower to be set at the western end of the block with a large plaza separating it from the Woolworth Building, one of the city's most important landmarks.

The tower will be clad in limestone and cast stone and will resemble to an extent Mr. Stern's design for the recently completed luxury apartment building at 15 Central Park West. Mr. Stern said that the 99 Church Street development "will counterpoint the glass-and-steel office towers that Larry Silverstein and his organization are building" at the World Trade Center redevelopment site.

Yabu Pushelberg is the interior designer for the hotel and Mr. Stern will design the hotel's public spaces.

Construction will begin in June and completion is anticipated for early 2011.

The hotel will have a "premier" restaurant, a spa and health club with pool and more than a quarter of its rooms will be suites. The hotel entrance will be on Barclay Street and the residential entrance will be a 30 Park Place.

Mr. Silverstein made his announcement at a breakfast meeting of the Alliance for Downtown New York and that organization's president, Elizabeth H. Berger said that "Larry Silverstain is a tireless advocate for Lower Manhatan and a major factor in Downtown's incredible revitalization."

Mr. Silverstein declared that "the sheer breadth and diversity of the new Downtown economy makes it more durable and more lasting than at any point in its history," adding that "from a population of about 14,000 in 1990, today more than 46,000 people live south of Chambers Street, a number that is projected to rise to 60,000 by the end of this year."

Silverstein Properties acquired the 11-story office building that formerly occupied the site at 99 Church Street in November, 2006, with the California State Teachers' Retirement System (CalSTRS) from Moody's Corporation for $170 million and Moody's has relocated its corporate headquarters to Silverstein Properties' 7 World Trade Center nearby.

Mr. Stern is the Dean of the Yale School of Architecture and the co-author of a monumental five-volume series on the history of New York City architecture.