DURST Fetner Residential has finally signed its contract with Mount Sinai Hospital to redevelop the pre-war apartment building at 1212 Fifth Ave. into two- and three-bedroom condominium apartments and build another tower for the hospital.

As part of the deal, DFR will oversee the development of a 43-story apartment building next door on East 102nd Street that will be designed by Rafael Pelli of Pelli Clarke Pelli and Peter Claman of SCLE.

To provide spectacular Central Park views, the apartments will rise above the 215-foot tall base needed to supply mechanical support for the Mount Sinai Center for Science and Medicine building that is now under construction on Madison Avenue.

While it could go to 542 feet, sources say the new tower will top off at 510 feet — slightly taller, and more beautiful, than the hospital’s Darth Vader-like Annenberg Building nearby at 99th Street.

While local civic groups fought the tower that was originally proposed at 600 feet, no other waivers were needed once construction of the adjacent Science building was approved by the BSA in October of 2008, according to the Board of Standards and Appeals.

DFR is a partnership between the Durst and Fetner families and is led by Hal Fetner.

Fetner said DFR has hired S. Russell Groves to design a “sustainable renovation” of 1212 Fifth.

“We will be keeping the beauty and charm of the classic pre-war building and melding it with modern touches,” said Fetner.

Additionally, he noted, they are “respecting the rights” of the nine remaining residential tenants in the building.

Those who move out of the 16-story building during construction will have their apartments remodeled, he said, but otherwise, DFR has tweaked the work to take place around them.

“We are talking to the tenants on a case-by-case basis,” Fetner explained, adding that they would also be offered the right to buy their units.

While a closing on the long-awaited deal with Mount Sinai won’t take place until the beginning of September, Fetner said DFR will immediately begin modernizing the elevators.

“In a perfect world, I would keep it as a rental,” he sighed, alluding to the expected high costs of the renovation.

Said the hospital in a statement: “The building is occupied primarily by Mount Sinai entities and employees who will vacate their apartments to allow the developer to complete renovations. Mount Sinai continues to work with Durst Fetner with regard to the design and potential development of a residential tower on the adjacent property.”

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To the chagrin of downtown supporters and elected officials, the Empire State Building is snatching the New York offices of the Federal Deposit Insurance Corp. from its roost at 20 Exchange Place, which is being converted to a residential building by Metro Lofts Management.

The federal agency that insures US bank deposits will be leasing a whopping 102,000 feet on the 12th and 13th floors, where the asking rent was in the mid-$50s.

Grubb & Ellis has the national contract to represent the FDIC.

Along with a $20 million green sustainability program as part of its $500 million capital improvement plan, the Empire State Building has an ongoing leasing scheme that consolidates small spaces into full floors.

According to CoStar Group, the FDIC will become its largest tenant after the agency considered other locations like 90 Park Ave. and space near transportation hubs like Penn Station and Grand Central Terminal.

Stephen Eynon, Daniel Bodner and Daniel Rodriquez-Sains of CB Richard Ellis handled the transaction for the complicated and layered Malkin-owned Empire State Building.

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The Catholic Museum wants to relocate to Washington, but first it needs an angel to buy its completely renovated headquarters at 443 E. 115th St., a former church that sits next to the Shrine of Our Lady of Mt. Carmel.

According to its Prudential Douglas Elliman listing, the price for the 22,500 square foot space was reduced to just under $5 million from $7.9 million.

More than $10 million went into the restoration of this 1884 structure, said the museum Executive Director Christina Cox.

Brokers Pamela Nichols and Jason Stojkovic say the building is in mint condition and perfect for a charter school, museum or art gallery.

A smaller vacant building and yard next door is also on the market.[email protected]