Those who know Brian Duperreault, president and chief executive officer of Marsh & McLennan Cos. Inc., know he’s shrewd and has a good turn of phrase.

Following a speech Mr. Duperreault gave recently at the Rendez-Vous de Septembre reinsurance meeting in Monte Carlo, he was asked what the key difference is between being on the brokerage side vs. working at an insurance company.

Mr. Duperreault should know. He spent most of his long career in insurance on the carrier side, at American International Group Inc. and then heading ACE Ltd., where he has been credited with building it into the global powerhouse it is today. He retired from ACE in 2006 as chairman and then came out of retirement to join MMC when former CEO Michael Cherkasky stepped down.

As to the difference in being a broker, the MMC chief quipped: “It’s instant gratification. When you bind a big piece of business, as a broker you celebrate. As a carrier, you don’t know whether to laugh or cry.”

(Senior Editor Sally Roberts is away. Guest blogging in the interim is BI Editor Regis Coccia.)