O’Connor Davies, LLP, one of the largest accounting and consulting firms in the New York tri-state area, has extended its lease while expanding for a third time at 500 Mamaroneck Avenue in Harrison, N.Y., according to Jeffrey H. Newman, executive vice president of Malkin Properties, the marketing and managing agent for the building.
O’Connor Davies will occupy an additional 3,144 s/f on the third floor, raising its total occupancy to 35,580 s/f, which it has leased through 2024. Malkin Construction will build out the additional space.

“Since initially coming to 500 Mamaroneck in 2001, O’Connor Davies has been pleased with the hands-on management at the property, the attention to detail toward the upkeep of the building, the extraordinary amenities provided for tenants, and its convenience to public transportation,” said John R. McCarthy of McCarthy Associates, who represented the tenant.
“From its initial lease signing through its expansions, O’Connor Davies has become well acquainted with Malkin Properties’ ability to accommodate a growing tenant and to work with them closely throughout negotiations. ”
“It’s always rewarding validation of our hands-on management when a tenant chooses to expand and extend its lease with us,” said Newman who represneted the landlord with senior leasing associate Kimberly Zaccagnino.
Attorneys involved included Peter Bassano of Bleakley Platt & Schmidt, LLP for the tenant, and David Bleckner and Ian Lester of David Bleckner, P.C., for the landlord.