Last year was a blockbuster for merger-and-acquisition activity in the asset-management sector — buyers spent nearly $44 billion to purchase 191 firms managing more than $2.6 trillion, according to a recent research report from investment bank Putnam Lovell NBF Securities. In fact, the volume of assets changing hands last year through M&A deals surpassed the combined volume of assets involved in deals during the previous three years. Among last year's deals were the sector's two biggest: Bank of New York's acquisition of Mellon Financial — the largest-ever fund-management acquisition in terms of both assets under management ($947 billion) and disclosed deal value (more than $16 billion) — and BlackRock Financial's acquisition of Merrill Lynch Investment Managers for a disclosed deal value of $9 billion.