There were an unprecedented 89 mergers or acquisitions involving fund-management firms in the first half of 2006. Buyers spent at least $13.5 billion in disclosed and estimated dollars — almost as much as the total spent for all of 2005 — to acquire nearly $1 trillion in assets. If this pace keeps up, deal volume in 2006 will top the previous high set in 2000. It isn't just mutual fund assets the buyers are after: Roughly 22 percent of the 89 deals involved alternative asset managers, such as hedge funds and real estate investment trusts. So what's driving all this activity? Following a painful three-year bear market, messy trading scandals and heightened regulatory scrutiny over fees and disclosure, firms are under greater cost pressure, says Jeff Keil, a mutual fund consultant in Littleton, Colo. Acquiring another asset manager can help by increasing a firm's scale, diversifying its product mix and widening access to distribution. Keil also notes that among publicly traded money managers, there is little patience on the part of shareholders to wait for meaningful organic growth.