Bankers Hit With Millions in Breakup Fees for Ditching New Jobs

Bankers are applying the idea of a “breakup fee,” a longtime fixture in corporate takeovers, to a very different kind of acquisition target: each other.

This story begins happily enough, with a nearly $10 million offer from Jefferies Financial Group Inc. The lucky hire was Dean Decker, a rainmaker at Credit Suisse Group AG.

The catch: If Decker reneged before he started, a clause in his nine-page offer letter read, he’d have to pay Jefferies what amounted to a personal breakup fee. The price to walk away: $4 million. Walk away Decker did.

Seven years later, the legal ...