R.J. Kelly Co. has completed the $90 million acquisition of 14 industrial properties across southern New Hampshire — the largest single acquisition in the Burlington, Mass.-based real estate firm’s 71-year history.

The properties have 34 different tenants and are located in in Hudson, Nashua, Salem, Londonderry, Manchester and Amherst, NH.

The acquisition closed in August.

The purchase is the latest industrial acquisition by the company, which last November bought the sprawling commercial property originally developed by printing press–maker Goss International in 1986 off Route 155A in Durham.

The latest acquisition, said Brandon Kelly, president and CEO of the firm, “adds significant synergies to our growing New Hampshire portfolio while providing an excellent opportunity for long-term stability and value creation for our investors.”

Brockton, Mass.-based HarborOne Bank arranged financing for the deal with a syndicate of four other lenders, providing a total of $76.3 million for the acquisition. The five-bank syndicate also included Salem 5, Westfield Bank, Service Credit Union and Bank Newport.

– JEFF FEINGOLD