A 106-unit multifamily portfolio in Somerville’s Spring Hill section has been acquired for $31 million.

Allston-based Nora LLC acquired the three adjacent buildings on 1.1 acres from Spring Hill Realty Trust, which developed the complex and owned it for nearly a century.

NAI Hunneman’s Carl Christie and Dan McGee represented the seller and procured the buyer. The property is located between Union and Porter squares with frontage on Summer Street.