Officials from the Metropolitan Transportation Authority are defending the Fulton Transit Center development project in Lower Manhattan, saying aspects of the project are under way but behind schedule by at least a year. Testifying in front of the City Council’s transportation committee yesterday, the MTA’s capital construction president, Veronique Hakim, said the underground portion of the project, which will connect 11 subway lines just east of the World Trade Center, is proceeding but would be delayed by at least 12 to 18 months. The first phase of the project was originally scheduled to be completed by the early part of 2009.

Unknown is the fate of the planned glass dome entrance to the transit center, which was originally designed to help illuminate the lower depths of the station and provide 20,000 square feet of aboveground retail at Fulton Street and Broadway. A domed oculus was included in the design by Grimshaw Architects, James Carpenter Design Associates and the engineering firm Arup.

In January, the executive director of the MTA, Elliot Sander, announced that plans for the entrance had to be scrapped because construction costs had pushed the project hundreds of millions of dollars over budget.

For the past several months the MTA has been exploring alternative plans for the entrance, and yesterday the director of special project development and planning, William Wheeler, confirmed that the authority is considering a proposal that would have a performing arts center currently slated as part of the redevelopment of the World Trade Center site built in place of the entrance to Fulton Transit Center.

“We have seen some concept drawings and we are considering those,” he said.

Mr. Wheeler told reporters that the chief executive of the Empire State Development Corp., Avi Schick, had proposed the idea.

A spokesman, Michael Murphy, said in a statement that Mr. Schick would prefers to see the Fulton Transit Center built as it was originally proposed, but “if that can not happen, the MTA will then need to evaluate other options that provide for an iconic transit center with meaningful public space. It is in that context we have talked about looking at the feasibility of locating a performing arts center on the site.” Local businessmen and residents have criticized the MTA for the delays.

In her testimony, the president of the Downtown Alliance, Elizabeth Berger, said residents, schools, cultural institutions, and small businesses were tired of waiting.

“Connections to the 11 subway lines is essential to Lower Manhattan. We can’t settle for less and we can’t wait any longer,” Ms. Berger said.

The use of eminent domain may become a factor in what the MTA ultimately constructs there.

Mr. Wheeler told Council Member John Liu that the possibility of selling the air rights above where the entrance of Fulton Transit Center is to be built was not a “workable option.”

A spokesman for the MTA, Jeremy Soffin, said a “number of factors” had made the sale of the air rights unfeasible.