Although the $1.3 billion tower is still under construction, about 300 employees in its corporate and investment banking unit moved into three floors on Monday. Another 200 will move into three more floors next week.

The relocation will be staggered into next year, spokesman Lawrence Grayson said. About 4,000 employees eventually will fill 34 of 51 occupiable floors. Third-party tenants such as law firms will start moving in this fall.

Employees are setting up in the building, known for a host of environmentally friendly features, even as work continues in the lobby and upper floors. The majority of the bank's New York workers, now located in leased locations around the city, ultimately will work in the skyscraper known as Bank of America Tower at One Bryant Park.

The corporate and investment bank will take about 60 percent of the bank's space in the building, while wealth and investment management will account for about 18 percent, Grayson said. The rest will be used by technology and support staff.

The skyscraper, set against the backdrop of Times Square and Bryant Park, is a crystalline symbol of the bank's growing New York presence. That has raised concerns in Charlotte that Bank of America could someday relocate its headquarters there. But chief executive Ken Lewis has worked to squelch those concerns by announcing plans for another tower and Ritz-Carlton hotel in the bank's hometown.