Both sides say they've given an update to the arbitration panel that set Friday's deadline.
They say that after "substantial discussions," they "have made progress toward resolving the issues surrounding the eastern portion of the World Trade Center site."
The building of planned towers at that part of the site has stalled in a dispute over financing. Silverstein wants more public money to build the towers, but the authority says it's better to delay construction on two of the towers until the real estate market improves.
