Work continues on the concrete core of 1 World Trade Center, the Freedom Tower, which is being constructed at Ground Zero.
The agency that owns the World Trade Center site has formally approved a deal with the site's developer over how to help pay for two towers there.
The Port Authority of New York and New Jersey voted Thursday. It had reached a tentative deal last spring with developer Larry Silverstein.
Port Authority Executive Director Chris Ward says stakeholders will share the financial risk in such a way as to protect limited public resources.
The deal calls for the Port Authority to put up $1 billion to help finance a 64-story building already under construction. The money would only be used if the building doesn't repay its debt.
The agency also has agreed to provide $600 million backup financing for a 71-story tower, if Silverstein finds tenants and raises $300 million in cash.
Silverstein lauded the agreement and thanked city leaders for helping to get it done.
"Downtown has emerged as one of the world’s most exciting mixed-use neighborhoods, offering an unparalleled blend of high-tech office space, retail, residential living and cultural attractions," he said in a statement. "This agreement will ensure that we continue this momentum with a new generation of cutting-edge, green skyscrapers becoming available starting in 2013."