The 93-unit apartment house at 1143 Second Ave. has gone into contract for $47 million to Stonehenge Partners. The all-cash deal for the partially stabilized building was signed yesterday and should close after Labor Day, sources said.

That should be good news for the tenants, as Stonehenge — run by Ofer Yardeni and Joel Seiden — is known for upgrading and maintaining its rentals and not cashing out into condos. While there are another 77,000 square feet of development rights, it is unclear if Stonehenge will build up or simply pocket them for a future play.

The building also has 15,000 square feet of retail on its 200-foot-long westerly blockfront that runs from East 60th to East 61st streets. The Jones Lang LaSalle team of Richard Baxter, Ron Cohen, Scott Latham and Jon Caplan marketed this one for sellers KFJ Realty, as we predicted back in June.

No one could be reached for comment.

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Back in April, Investa Property Group said it wanted out of its 49 percent share of 900 Third Ave. on the northwest corner of East 54th Street. Now we’ve learned it is finally interviewing local brokers to figure out the value and hand out the assignment.

Paramount had sold the stake to the then-ING Office Fund/Clarion Partners as the Sydney-based company’s first US investment back in 2003 for a mere $107.7 million. Investa took over and now wants to focus on its Australian properties.

According to a 2003 Commercial Real Estate Direct report, the owners had an equal say on major decisions and a buy/sell agreement, but it is unclear if that agreement is still in effect. The building carries a $270 million mortgage from 2007.

The 36-story, 595,105 square foot Class A tower is now around 90 percent leased. At a going rate of around $800 a square foot for quality properties, Clarion should pocket around $230 million for its half-share.

Paramount and Clarion reps did not return calls, and no one replied to an e-mail to Investa.

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The venerable Empire State Building has taken a modest mortgage of $159 million from HSBC that can be increased to $235 million. Documents show that the funds will help pay for its ongoing energy-efficient capital-improvement programs, and sources said it is part of a larger financing package. The ownership could not be reached for comment.

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The music talent firm MBK Entertainment, which represents Alicia Keys, Tyrese Gibson and others, has signed a seven-year lease to move its city offices and recording studio from 240 W. 35th St. to 7,583 square feet at 519 Eighth Ave. It will keep its Teaneck, NJ, office. The company has a record label, along with music, film, marketing and branding divisions.

Alan Bonett of Adams & Co. Real Estate represented the tenant while Steven Kaufman and Barbara Raskob of the Kaufman Organization represented the ownership in the transaction, which had an asking rent in the high $30s per square foot.

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In other entertainment news, “American Idol” ‘s producer, FremantleMedia, which also produces “America’s Got Talent,” “The X Factor,” “The Price is Right” and “Family Feud,” will relocate to 8,000 square feet on part of the fourth floor of 435 Hudson St. in Hudson Square. The company is currently located at 63 Madison Ave.

Last fall, FremantleMedia acquired a 60 percent share of 435’s tenant, @radical.media, which creates innovative advertising and branded entertainment content and has about 55,000 square feet on the sixth and seventh floors. After renovations, the move at the end of this year will consolidate the companies in one location with coterminous leases.

Jeffrey Peck and Gary Kerper of Studley represented the tenant in the transaction.

Building owner Trinity Real Estate had an asking rent in the $40s a square foot and was represented in-house by Marc Packman and Peter Fontanetta.

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Moelis & Co., headed by Kenneth Moelis, is expanding at 399 Park Ave. into a sublease of 24,662 square feet on part of the sixth floor, which had an asking rent of $60 a square foot.

Louis D’A vanzo of Cushman & Wakefield rep resented the ten ant in the six- year sublease from Legg Mason, which was repre sented by a CB Richard Ellis team of Scott Bogetti, Ramsey Feher, Christopher Mansfield and Kenneth Rapp.

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Finally, the haunted house Blood Manor has leased the entire second floor of 9,000 square feet at 163 Varick St. at the southwest corner of Charlton Street for a new installation of their acclaimed attraction.

Colonial Hardware recently sold the building and moved out. The tenant was represented by Tom Pfingst of Kenneth Zund Realty, while the build ing owner was represented by Edwin Shira zian of Heritage Realty, which had an asking rent of $30 a square foot. “They will have signage on the building,” said Pfingst.

Blood Manor had been located in Chelsea at 542 W. 27th St. for the last five years and will reopen at the new location in Hudson Square in time for the Halloween festivities. [email protected]