Boston-based Paradigm Properties has announced four new property management contracts for commercial properties in Cambridge and Boston.

The new assignments consist of the office complex Cambridge Park at the Alewife T Station in West Cambridge, and an eight floor, multi-tenant office building, The NonProfit Center, at 89 South St. in Boston.

"We are very pleased to add these outstanding properties to our management portfolio," said John Caldwell, managing director of Paradigm.

Cambridge Park is comprised of three multi-tenant office buildings at 100, 125, and 150 Cambridge Park Drive in Cambridge, which totals 572,000 square feet.

Paradigm was selected by two separate owners: Archon Group LP, an international investment management and real estate services firm, and Transatlantic Investment Management Inc., an investment and property management company based in Cambridge, the company said.

The building at 89 South St., also known as Third Sector New England’s NonProfit Center, is a 110,000-square-foot property developed in 2004 to provide affordable office space for a diverse community of nonprofit tenants.