AllianceBernstein forecloses on Onyx’s 1311 Mamaroneck offices

A Luxembourg lender has filed a foreclosure action on 1311 Mamaroneck Ave., a massive White Plains office complex that once housed IBM offices.

AB Commercial Real Estate Debt, an affiliate of AllianceBernstein, the global investment management firm based in Manhattan, claims that an Onyx Equities affiliate defaulted on the mortgage in January and owes more than $30.5 million.

AB Commercial demanded that the enormous office complex be sold to pay off the debt, according to a complaint filed Feb. 24 in Westchester Supreme Court.

The 23-acre property borders the Hutchinson River Parkway and is across the street from Saxon Woods Park.

The 1311 Mamaroneck Ave. building was built in 1982 and comprises three floors with 327,311 square feet. Three sections have their own entrances and lobbies, making it appear as if there are three separate buildings.

IBM vacated the complex in 1997. The Jack Parker Corp. then converted the sprawling, single-tenant structure to a multitenant corporate campus, attracting organizations such as Gerber Life Insurance and the Leukemia and Lymphoma Society.

Onyx Equities, based in Woodbridge, New Jersey, acquired the building for $13.9 million in 2006, according to Westchester property records, and sold it to Caf West for $81.8 million in 2008.

The new owner defaulted on its mortgage, and Onyx bought back the building for $40 million in 2014.

Then OSG Mamaroneck LLC, an Onyx affiliate, borrowed $35.15 million from AB Commercial, according to the complaint. Phalanx Fund III LP, another Onyx affiliate, guaranteed payment of the debt.

When the loan matured on Jan. 11, the complaint states, the Onyx entities defaulted by failing to pay principal, interest and other fees totaling $30,505,000.

AB Commercial is represented by Manhattan attorney Scott T. Tross.