A UBS trader in his 20s said that like many of his peers at the firm, he would have preferred a job in New York City, where he lives.

“I mean, it’s annoying,” said the trader, who asked that his name not be used because he was not authorized to speak about the possible relocation. “I take Metro-North. I live pretty close to Grand Central, so it’s not a terrible commute. But it’s not ideal.” The trip takes about 45 minutes to an hour, depending on how many stops the train makes.

He added that “the bank’s plan is to move to New York, but it’s mostly to be closer to clients.”

UBS has hired the real estate brokerage firm CB Richard Ellis to explore new space. A UBS deal would also be a vindication of a multibillion-dollar effort to rebuild the World Trade Center complex. After the terrorist attack on the trade center, there was widespread debate over the future of the city’s financial center downtown. Since then, the residential population there has swelled.

Last month, Condé Nast, publisher of Glamour, The New Yorker and Vanity Fair, signed a deal to be the anchor tenant of 1 World Trade Center, the signature skyscraper at the northwest corner of the site.

Mr. Silverstein has the right to build three towers along Greenwich Street. The first one is already under construction, and the city has pledged to take space in it. But he has long sought a large financial tenant for what is known as Tower 3, which features five trading floors at the base, and will be built before Tower 2. A possible UBS relocation, which was first reported by Bloomberg News last week, would be a major blow to Stamford, where a quarter of the office space is vacant.

Mayor Michael Pavia of Stamford said UBS executives had been noncommittal, saying they had “no firm plans, nothing that they can report at this time.”