Eaton Vance has agreed to acquire the assets of Maryland-based fund manager Calvert Investment Management for an undisclosed sum.

Calvert will operate as Eaton Vance affiliate Calvert Research and Management following the completion of the deal.

The deal is expected to be wrapped up on or about 31 December 2016, subject to Calvert Fund shareholder approvals.

Eaton Vance vice president and CFO Laurie Hylton said: “The acquisition of Calvert provides significant potential benefits to Eaton Vance shareholders, both long-term and near-term. Calvert is a leading brand in one of the most promising categories of investing, and we expect to help them achieve substantial growth over time.

“Reflecting the current profitability of acquired operations and anticipated cost savings, we also expect the transaction to be immediately accretive.”

Calvert, an indirect subsidiary of Ameritas Holding Company, was set up in 1976. The company focuses on the responsible investment sector, offering actively and passively-managed US and international strategies, fixed income strategies and asset allocation funds. As of 30 September 2016, the company managed about $12.3bn in fund and separate account assets.

Calvert president and CEO John Streur said: “By combining Calvert’s expertise in sustainability research with Eaton Vance’s investment capabilities and distribution strengths, we believe we can deliver best-in-class integrated management of responsible investment portfolios to investors across the US and internationally.”