Asset manager BlackRock has acquired the fund of funds business of the Quellos Group, a boutique investment firm in Seattle in a $1.7 billion deal. The acquisition will give BlackRock a fund of funds operation of more than $25.4 billion. Under the terms of the agreement, the Quellos Group will receive $562 million in cash and $188 million in BlackRock stock. The acquired company could receive as much as $970 million in cash and stock over the next three years, based on performance targets. The chief executive of Quellos, Jeffrey Greenstein, said he would retire after the deal closed. The firm manages more than $20 billion in assets.