The law firm Phillips Nizer is leaving Kushner Cos.’ 666 Fifth Ave. for space at 485 Lexington Ave.

The 10-year deal is for 38,243 square feet — the entire 14th floor. The 31-story building sits between East 46th and 47th streets by the north entrance to Grand Central Terminal.

“We’ll no longer have the giant senior partner offices,” said the law firm’s managing partner, Marc Landis, who is giving up one of them. The firm will also use conference rooms for collaborative space.

Alexander Chudnoff and Abraham Cooper of JLL represented the law firm along with its in-house lawyers Landis, Robert Bachner and Steven Rabinowitz.

SL Green was represented by another JLL team led by Paul Glickman, Benjamin Bass and Diana Biasotti, working closely with David Kaufman, in-house at SL Green.

Lawyer Joseph De Vesta of Loeb & Loeb represented SL Green.

Asking rents at 485 Lex have been in the $70s and $80s per square foot.

The law firm had signed a two-year renewal lease at 666 in Nov. of 2015 for its 49,846 square-feet on two floors with an eye on moving elsewhere since the Kushners made it clear they wanted to empty their office tower to redevelop it with luxury condominiums and a larger retail base.

Meanwhile, Charles Kushner has been scouring the world for funds to cover the ambitious project and pay off its current mortgage. His son, Jared Kushner, sold his stake in the building to a family trust while he works at the White House for his father-in-law, President Trump.

Kushner Cos. pocketed $25 million at the end of August by flipping their contract on the Jehovah Witnesses’ residential building at 90 Sands St. in Dumbo Heights to their partner, RFR.

The building had been looked at as a future hotel site to be developed along with Ian Schrager, but as that industry has retrenched, they decided not to move forward.

Sources said RFR is still weighing their options.

Meanwhile, Kushner Cos. remains invested in Brooklyn with 2 million square feet of offices plus its 1 million square-foot 85 Jay St. development site now being prepared for a Morris Adjmi-designed 21-story residential and office tower.