Designs for the east side of the former World Trade Center site will come to light on Thursday in a press conference featuring developer Larry Silverstein, officials from the Port Authority, and three acclaimed architects, Sir Norman Foster, Lord Richard Rogers, and Fumihiko Maki.

While the design of the Freedom Tower and the World Trade Center Memorial have been through a bumpy public review process, the plans for the three soaring office towers proposed along Church Street have been sealed off behind closed doors. The three buildings will contain about 6.2 million square feet of office space, and will share a common podium and underground infrastructure, including retail space.

Messrs. Rogers and Maki were officially named as architects in May, joining Mr. Foster and a bevy of other star architects working at ground zero. Since then, architects and engineers from their firms have been sharing office space and drawing up designs on the 25th floor of 7 World Trade Center, overlooking the site.

The site’s Master Plan, conceived by architect Daniel Libeskind, calls for three towers along Church Street with slanted roofs, descending in height from north to south.

Mr. Silverstein said this week that it was a challenge to work with “three major egos,” but he said that the result was “three truly magnificent architectural buildings.”

The executive director of the New York chapter of the American Institute of Architects, Fredric Bell, said the announcement would end five years of anticipation regarding the final look of ground zero.

“This is a big deal. We are building another city here by most city’s standards of urban planning,” Mr. Bell said. “So far, the cards have been held pretty close to the chest.”

Mr. Bell said that selecting three well-known architects was a “safe bet,” but he said there is some fear in the architectural community that the designs “will have nothing to do with each other, nothing with the site, and nothing with the Master Plan.”

The largest of the buildings, known as Tower 2, will be designed by Mr. Foster, whose work includes the recently completed Hearst Tower in Midtown and “The Gherkin” building in London. As planned, Tower 2 would be the fourth tallest building in New York.

To the south of the new transportation hub, designed by architect Santiago Calatrava, will be Mr. Rogers’s Tower 3, slated to rise about 1,050 feet and contain about 2 million square feet of office space. Mr. Rogers is also one of the designers of the Javits Convention Center expansion. His previous projects include the Millennium Dome in London and the Pompidou Center in Paris.

The smallest tower, Tower 4, is designed by Mr. Maki, who won the Pritzker Prize in 1993. He is also designing a 35-story tower that will serve as a temporary home to the United Nations as its current residence is renovated.

For construction to proceed on the three buildings, the Port Authority, which owns the site and leases it to Mr. Silverstein, must complete the construction of an underground wall known as the “east bathtub,” expected in mid-2008. Towers 3 and 4 are scheduled to be finished by 2011, and Tower 2 by 2012.