Carlyle Group -– the mammoth private equity group that manages $82.7 billion in 60 funds worldwide and recently, with Ashkenazy Acquisition Corp., bought 650 Madison Avenue for $680 million -- is purchasing this deal in partnership with Stanley Chera's Crown Acquisitions. The 49 percent stake, as reported by Bloomberg News, in the approximately 90,000-square-foot retail portion, which includes a Brooks Brothers and the NBA Store, is valued in the deal at $525 million.

Kushner Companies added value to the deal by buying out the remainder of the Brooks Brothers’ below-market lease, which was originally scheduled to expire in 2014. Now, Brooks Brothers will vacate by Jan. 31. Abercrombie Kids recently signed a lease to occupy half of the Brooks Brothers space starting Feb. 1 at an estimated $2,500 a square foot

Jeffrey Roseman, executive vice president of Newmark Knight Frank Retail, said that's the highest retail rent in the city "by a country mile."

"The highest deal before that was Armani; that was maybe $1,600 ot $1,700 a foot at 717 Fifth Avenue," Mr. Roseman said. "That stretch of Fifth Avenue is just incredible. ... Probably the highest-grossing stores per square foot in New York are Abercrombie & Fitch at 56th and Fifth and the Apple Store at 58th and Fifth. Those stores are doing anywhere between $6,000 and $10,000 a square foot. In New York, a store is considered successful if it earns $800 a square foot."

“This sets a new rent level, but we’ve been close to that before," added Faith Hope Consolo, chairman of Prudential Douglas Elliman's Retail Leasing and Sales Division. “That’s a new high. But you know what, it’s a corner, it’s got huge frontage, it’s a southbound corner on a southbound street. It doesn’t get any better.”

The retail space has more than 200 feet of frontage on the gilded Fifth Avenue.

The deal, which is being financed by Barclays and SL Green and was brokered by Carlton Group chairman Howard Michaels, comes at a good time. This transaction will allow the Kushner Companies to pay off $335 million in short term debt obligations.

Kushner will retain a 51 percent interest in the retail condo as well as continue to own fully the 1.45 million-square-foot office tower where it's located. (Jared Kushner, a principal at Kushner Companies, is The Observer's publisher.)

A spokesman for Kushner Companies had no comment.