Nelson Peltz in his office in New York
(Fortune)
Activist investing can occasionally seem like a reality-TV mud fight, what with Bill Ackman and Carl Icahn recently brawling over Herbalife stock and David Einhorn suing Apple to get the board's attention. Then there's Nelson Peltz. He has become adept at using his clout as a shareholder to push for changes aimed at creating value for shareholders. At age 70, Peltz has experience running a Fortune 100 company (Triangle Industries). He and his partners at Trian Fund Management, Peter May and Ed Garden, have built a legacy of successful investments in companies such as Heinz (where Peltz's 2006 campaign sparked improvements that culminated in the recent news that Berkshire Hathaway will buy the company) and Kraft (he argued for the spinoff of the company's snacks unit into what is now Mondelez). These days, they can often bring about the changes they're seeking through more diplomatic means: Peltz & Co. deliver detailed white papers that lay out paths to change and higher stock prices. Peltz talked with Fortune about the potential return of mergers and acquisitions (which he is betting on via a position in investment bank Lazard) and some of his current investments. Edited excerpts: