The Port Authority is looking for a partner to help build the central tower at the World Trade Center site.

The agency has solicited bids from a group of real estate developers in an effort to create a partnership interest in 1 World Trade Center.

The Port Authority hopes to raise at least $100 million dollars for the $3.2 billion project.

The agency also wants the would-be partner to take on marketing and lease negotiating with corporate tenants, at a time when demand for office space is down.

The building 1 World Trade Center is slated for completion in 2013.