Terms of the deal were not disclosed.
The acquisition, which is expected to close in the third quarter, includes a payment at closing in addition to a contingent payment dependent upon Standishs future performance. The firm will remain in Boston but will change its name to Standish Mellon Asset Management, Mellon said.
Standish, Ayer & Wood, founded in 1933, provides investment services to institutional and high- net-worth clients as well as to its proprietary family of 21 mutual funds with a total of $4 billion in assets under management. The firm had been privately held by its 46 directors.
The acquisition will add about $41 billion to the $520 billion Mellon already has under management. It will also add significantly to Mellons fixed-income capability and allow the firms to cross market products and services to each others' clients, said Steven G. Elliott, Mellon senior vice chairman and CFO in a prerecorded telephone message.
Mellon is the parent of The Dreyfus Corp.ration of New York, The Boston Company Asset Management of Boston, and Newton Investment Management Limited of London.