NEW YORK—The Davis Companies, based in Boston, Mass., and Onyx Equities LLC, based in Woodbridge, N.J., have acquired Atria West, a 250,000-sq.-ft., class A office building at 900 Stewart Ave. in Garden City, N.Y.

The joint venture ownership has named the Rochlin Organization to serve as exclusive leasing agent for the property, while the Spector Group will serve as architect for planned renovations. The new ownership plans upgrades to the atrium lobby, common areas, outdoor plaza and landscaping.

Constructed in 1986, Atria West stands six stories tall. The property includes a 180-ft.-long, 50-ft.-high atrium. Amenities at the property include a café, management office, outdoor seating, 24/7 access, security system and parking.

Located in the Nassau County submarket, the property is in close proximity to Adelphi University, Hofstra University, Nassau Community College and Roosevelt Field Mall. Current tenants include JP Morgan Chase and AT&T.

“We had been searching for the right opportunity to expand our portfolio in the dynamic Nassau County market, so we are excited to have acquired this premier site in one of the largest office deals completed on Long Island in 2012,” Onyx Equities SVP of Investments Stephen Sullivan said. “We look forward to working with the Spector Group, which was the original architect on the project, to upgrade the building, and with the Rochlin team to identify high caliber tenants.”