Discount retailer Daffy’s is facing a lawsuit from Charles Cohen, who claims the chain backdated a renewal option for its East 57th Street store and thus should be booted out of his building.

“I am outraged and shocked that somebody would resort to a cover-up instead of reaching out in advance,” Cohen told The Post.

Daffy’s settled into nearly 50,000 square feet in mostly underground levels of 135 E. 57th St. in 1994, long before Cohen bought the building.

The space includes a 4,000 square foot ground-floor entry that leads to two 25,000 square foot selling floors accessed by an escalator and elevator.

The office property, with a sweeping semicircular plaza, also has a large marquee and numerous flags emblazoned with Daffy’s name to ensure its visibility from nearby avenues.

Sources said Cohen worries that not only does the signage degrade the property, but that the space could fetch perhaps twice what Daffy’s would be paying — under $40 a foot for the five years starting in February 2011.

According to Cohen’s suit, which was filed in state Supreme Court in Manhattan on Feb. 1, Daffy’s lease would expire on Jan. 31, 2011, unless an option was exercised at least a year in advance through a notice delivered by certified mail or by an “overnight courier service.”

Cohen claims he got Daffy’s notice on Feb. 4 by both e-mail and by fax and that it was “backdated [to] Jan. 30, 2010.” On Feb. 9, he got the same notice by regular mail, postmarked Feb. 5.

He goes on to say that Daffy’s created a “fraudulent scheme of backdating” its option notice and did not send it in either a timely manner or through the methods set out in the lease, which required a signed receipt.

The complaint says Daffy’s already said it will go to court to retain possession.

A Daffy’s spokesman did not return a call for comment.

The building is no stranger to lawsuits. Cohen’s father Sherman once sued Donald Trump over the word “International” after Trump announced the name of his then-upcoming hotel as Trump International Hotel & Tower.

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Wyclef Jean‘s charity for Haiti may be calling from a former Avon floor at 1251 Avenue of the Americas.

With Avon moving out of the third through sixth floors in the Mitsui Fudosan-owned tower, the space will soon be available.

Sources said the Yélé Haiti Foundation is now in negotiations to sign a deal for one of the Avon floors, which could be as much as 40,000 square feet.

“They are a big charity,” a source said.

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First-round bids for the 159-unit Carlton House Hotel are due this week, sources said, through Darcy Stacom and Bill Shanahan at CB Richard Ellis.

The long-term residence hotel has attracted a groundswell of brick kickers from all over the world as there is a dearth of available properties.

It’s unclear how many of the more than 100 that made inquires will actually make formal bids, but it only takes two to start a bidding war.

The Madison Avenue hotel has 150 years left on its ground lease.

The brokers did not return calls for comment.

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The vacant 160 Lexington Ave. is up for grabs.

The 1909 former banking building at East 30th Street was last renovated in 1987.

The seven-story building has distinctive column details. Its 21,700 square feet was once home to Touro College.

Howard Kessler, Barry Berkowitz and Jordan Gosin of Newmark Knight Frank are pitching the building for sale or lease with no asking prices, but at $300 to $400 a square foot, the property would cost less than $10 million.

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Private security firm Securitas Security Services USA has signed an 11-year lease for the entire 17th floor of 17,500 square feet at 1412 Broadway.

The deal took a speedy six weeks to complete and the lease was ex ecuted in eight days.

Nicky Heryet and Mark Furst of Colliers ABR represented the tenant.

The building was represented by Jesse Rubens of Murray Hill Properties. [email protected]