NEW YORK CITY-SL Green Realty Corp. has formed a joint venture with Stonehenge Partners to acquire eight retail and multifamily properties for $416 million. Stonehenge, which already owns and manages 2,560 apartment units in New York, will manage the residential portion of the properties.

The properties under contact in the joint venture are 724 Fifth Ave., 752 Madison Ave., 19-21 E. 65^th St., 762 Madison Ave., 44 W. 55^th St., 400 E. 57^th St. and 400 E. 58^th St. According to the David Frankel Realty website, the company owns the buildings being purchased.

Several of the buildings are already occupied by high-end fashion tenants. For example, luxury retailer Prada now occupies roughly 20,700 square feet at 724 Fifth Ave. And at 752 Madison Ave., where the joint venture plans to acquire interests, Armani has a sub-lease agreement in place for the entire four-stories until 2025. SL Green already owns retail properties in the area, for example 717 Fifth Ave., where Giorgio Armani has its flagship location.

Faith Hope Consolo, chairman of retail leasing, marketing and sales at Prudential Douglas Elliman Real Estate, says that the acquisitions--in prime buildings on or near Fifth Avenue’s “Gold Coast”--will take SL Green to a whole new level.

“You don’t get any better than that,” she says of the 724 Fifth Ave. location, in particular. “The neighbors are Abercrombie and Bulgari--it’s next to the Crown Building, which has all of what we call the high street jewelers.”

According to data from CB Richard Ellis, the Plaza District saw average asking rents hit $86.08 per square feet for the second quarter of 2011. The area led the market and had a significant increase over the same period of the previous year, when average asking rents were roughly $60.75 per square foot.

As for the over 400 units included in the residential component, the partnership plans to implement a capital improvement plan for most. The 260 multifamily units at 400 E. 57^th St. will see improvements to building amenities.

SL Green didn’t return calls from GlobeSt.com seeking comment, however company president Andrew Mathias touched upon the significance of the multifamily portion of the portfolio in a prepared statement.

“This is an exciting opportunistic investment for SL Green, which already has an outstanding track record in acquiring and repositioning New York City office and retail properties,” Mathias said. “We also are excited about making our first significant equity investment in the multifamily area, which helps to diversify our portfolio further while still maintaining our New York City focus.”

Ofer Yardeni, managing partner and co-founder of Stonehenge, said that the group looks “forward to collaborating with the SL Green team in repositioning these properties and bringing them to their full potential value.” Stonehenge, which focuses on Manhattan real estate investments, currently owns and manages a portfolio with its investment partners that is valued at $1.8 billion.