'This is another step forward in the redevelopment of the historic site,' said Candace McAdams, spokeswoman for the Port Authority of New York and New Jersey.

'The Freedom Tower is an iconic structure that calls for a world-class dining destination.'

The restaurant on the 100th and 101st floors, offering 360-degree views of the area, is scheduled to open in 2013. The Port Authority on Tuesday will issue a formal request for expressions of interest to design, build and operate the restaurant.

With construction under way on the foundation, the 541-metre tower is expected to open in 2012, 11 years after the attack on the twin towers of the World Trade Center.

The 106th and 107th floors of the north tower were occupied by the Windows on the World restaurant. All restaurant staff members and breakfast patrons who were present died when American Airlines Flight 11 hit the tower on Sept 11, 2001. -- AP