Marchionnes last public appearance was June 26, and the company said July 5 he underwent surgery on his right shoulder and was expected to require a short period of convalescence.. Manley will also assume responsibility for the entire North American region, and is expected to implement the five-year business plan laid out by Marchionne at the beginning of June.
With Manley at the helm, Jeep - dubbed one of America's top three most patriotic brands in a Brand Keys study published last month - has more than trebled sales, breaking through the one million mark a year ago and becoming the main driver of profits for the entire FCA group.
Sergio Marchionne, who was replaced this week as CEO of the automaker, is in intensive care at a hospital in Switzerland, as reported by the Italian newspaper La Stampa and relayed by Crain's Automotive News. His credentials include running the profitable Jeep and Ram brands and he also built the company's presence in Asia.
Manley joined the automaker in 2000 and has led Jeep for almost a decade.
"It's an end of an era with the iconic, highly quotable, sweater-wearing Sergio Marchionne stepping down, with significant very concerns about his ailing health", said Rebecca Lindland, executive analyst at Kelley Blue Book.
Indeed, Marchionne split the Maranello manufacturer into a separate trading company, resulting in a considerable financial return for the Agnelli family and other shareholders. He also serves as CEO and chairman of Ferrari, and CNH Industrial.
Fiat Chairman John Elkann, in a letter to Fiat's 236,000 employees Sunday, called Marchionne a "true, rare kind of leader" and lauded him as "the best CEO that anyone could ask for and to me personally, a true mentor, partner, close friend".
The Agnellis still have a controlling interest in all three companies. Analysts estimate that Jeep alone could be worth the entire market value of Fiat Chrysler.
"The succession plans we have just announced, even if not without pain from a personal point of view, mean we can guarantee the maximum possible continuity, preserving our companies' unique cultures", said Elkann.
In his time at Ferrari, Marchionne ruffled feathers, both within the company and in F1.
CNH Industrial said its interim CEO, Derek Neilson, will continue on pending the selection of a permanent replacement for Marchionne.