SPRINGFIELD, N.J. — Hillsborough, N.J.-based Larken Associates has acquired a 106,880-square-foot retail and office property located at 899 and 901 Mountain Ave. in Springfield. The first building, Echo Plaza Shopping Center, is a 66,000-square-foot retail complex. The other building, Echo Executive Plaza Office Building, is a three-story, 40,880-square-foot professional office building. Larken Associates plans to undertake significant renovations and upgrades to the property. Construction at Echo Plaza Shopping Center will include a new exterior façade and roof, new tenant signage, a new marquee sign and exterior landscaping. Improvements at Echo Executive Office Building will include a new lobby, common bathrooms and corridors. Victor Kelly of Raider Realty represented the buyer in the transaction. The seller, as well as the purchase price, was not disclosed.