The business of underwriting bonds is being turned on its head in the U.S.

Gone are the days when money managers would passively wait for Wall Street banks to pitch them deals. Now, they're often the ones cooking up sale plans with corporate issuers, haggling over maturities and interest rates before taking them to the banks to finish off the transactions. The goal: Carve out and keep a chunk of the new debt, a precious commodity in a market awash with cash after years of central banks' easy-money policies, before letting Wall Street distribute the rest.

It's a transformation that's been building since BlackRock Inc., the world's biggest fund manager, brought in a former Bear Stearns Cos. banker to start a capital markets group five years ago, a hiring that helped mark investors' intentions to drive more of the process. Babson Capital and AllianceBernstein Holding LP, among others, have since followed suit.