HIP-hop mogul Russell Simmons and his estranged wife, Kimora Lee, founder of Baby Phat, have hopped over to Seventh Avenue for new offices for Simmons Jewelry.

The growing jewelry line was founded in 2004 with Fabrikant & Sons.

Simmons chose 10,000 feet comprising the entire seventh floor of 462-468 Seventh Ave. because sources said he wanted to be near his main offices at 512 Seventh Ave.

The asking rent was $40 a foot for the seven-year deal.

Barbara Adler represented the Kaufman Organization ownership in-house while entertainment brokers Brian Waterman, Lance Korman and Erik Harris of Newmark Knight Frank brought over the rap star and his family jewels.

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A tasty parcel on the northeast corner of 59th St. has just come on the market and will likely trade for well north of $100 million.

“This is a once in a lifetime opportunity,” said Bill Shanahan, vice chairman of CB Richard Ellis, who is running the offering with skyscraper queen Darcy Stacom.

“It doesn’t get much better than this.”

Of course, there is a catch: The long-term family owners are merely selling the land. The buyer won’t get to run the 140,000-foot emerald façade, Emery Roth & Sons-designed building on top of it for another 45 years.

However, you do get an income stream – with payments from Ironwood Realty – and the rent will eventually reset upward based on the value of the land.

But you count on that last part as a set up for dueling appraisals.

Retail tenants include Searle and Di Modolo while office tenants are mainly of the medical variety.

And it’s surrounded by some of the world’s priciest retail and offices.

Nevertheless, at the Real Estate Board of New York’s annual dinner last week, one of the industry’s prolific traders quipped, “I won’t be alive in 45 years. This is negative arbitrage.”

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If you’d rather own an entire kit and caboodle, The 39th Street Fashion Center is being marketed and should sell in the $90 million range – or around $400 for each of its 200,000 feet.

The Cushman & Wakefield’s fearless foursome of Jon Caplan, Scott Latham, Ron Cohen and Richard Baxter are heading up the offering that could lead to an investment or a full purchase.

The current owners, L&L Holdings, want to either replace partner Investcorp or completely walk away from the property.

“The market will tell us,” said Robert Lapidus, a partner and one of the “L’s” with David Levin- son.

Tenants are focused on young women’s ready-to-wear with Anna Sui the largest at 20,000 feet. Rents are in the high-$30s to low-$40s a foot.

The duo bought the old manufacturing structure in 2000 for $19 million with Carlyle, and after an extensive redo and repositioning took them out and recapped it in 2005 for $45 million with Investcorp.

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Portfolios to watch: Eastdil Secured has two full portfolios on tap. An entire Beacon Capital Fund of cross-country assets is being offered for $4.5 billion.

Locally, the portfolio includes properties at 237 Park Ave. and 100 Wall St.

Another group of assets are for sale by Broadway Partners and include the boutique office tower topping Barney’s at 660 Madison Ave., along with a gaggle of goodies in Boston.

Broadway Partners is keeping that city’s John Hancock Building, which it just bought from Beacon.

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