The Wednesday agreement allows Related to delay closing until office vacancy rates drop to 11 percent and co-op and condo prices hit $1,200 per square feet.
The MTA owns the land known as Hudson Yards for Long Island Rail Road operations.
In December, the City Council approved a rezoning plan for half of the 26-acres for apartments, cultural space and a new public school. The other half was rezoned in 2005. It allows for office, hotel and retail space and public open areas.
