Morgan Stanley will buy the investment management firm Eaton Vance in a deal valued at about $7 billion.

Boston-based Eaton Vance has over $500 billion in assets under management.

Morgan Stanley has actively gone after potential targets this year. The proposed acquisition Thursday comes just days after it closed on one of the biggest deals on Wall Street since the 2008 financial crisis, the $13 billion takeover of E-Trade Financial.

Eaton Vance will add more fee-based revenues to Morgan Stanley’s investment banking and institutional securities franchise, Chairman and CEO James P. Gorman said in a statement. The deal will give Morgan Stanley’s investment management arm approximately $1.2 trillion of assets under management and more than $5 billion of combined revenues.

The deal is expected to close in the second quarter of next year.