The agency building a signature skyscraper at ground zero is searching for investors to help market it in a flat real estate market.

The Port Authority of New York and New Jersey has asked developers to bid for a partnership in the $3.2 billion tower.

The developer would pay about $100 million. It would be responsible for leasing office space in the 1,776-foot-tall tower.

The proposal to sell off 1 World Trade Center, also known as the Freedom Tower, has been floated before. Some politicians fear a possible terrorist target would be a hard sell for companies.

Port Authority spokesman Stephen Sigmund said Monday that 1 World Trade will be one of the safest and most secure buildings in the world.