The rebirth of Allentown's downtown has taken a big step forward.

A major corporate player that moved in and brought hundreds of workers with it officially opened for business Monday.

National Penn Bank held a ribbon cutting ceremony Monday for its new headquarters at the Two City Center building located at 7th and Hamilton streets.

Developers and business leaders said it's proof that tax dollars generated through the Neighborhood Improvement Zone, or NIZ, are working for the city of Allentown.

Two City Center is the first building funded through the NIZ to be up and running.

National Penn is the first tenant to occupy the 11-story building.

"The NIZ was helpful to make sure there is economic development that takes place in a downtown urban setting. With everything that goes on with banking and economic development, it was a perfect fit for National Penn," said Scott Fainor, president of National Penn.

"It's going to re-establish Allentown as the center of the financial community in the Lehigh Valley," said J.B. Reilly, president of City Center Lehigh Valley.

Nearly 300 bankers will work out of the top five floors of the new 300,000-square-foot facility.

The other six floors will house a variety of businesses.

Developers said it's the first of many new businesses headed for the NIZ.

"There is a lot of development underway. There is a lot of development that has just begun and more development plans. It will be an active few years in downtown Allentown," Reilly said.

One City Center and the Lehigh Valley Phantoms hockey arena are the next NIZ-funded buildings set to open.