He spoke from headquarters in the Italian town of Turin, where corporate flags flew at half-mast.
However, board member Louis Camilleri replaced him as chief executive of the supercar manufacturer, while John Elkann, who is the chairman of Fiat Chrysler, became the chairman of Ferrari as well.
He added bankrupt U.S. auto maker Chrysler to the Fiat stable in 2009. "The company was in such bad shape, being stripped of any kind of resources by the previous owners".
Vettel, who is leading Ferrari's challenge to Mercedes, was out in front of this year's championship until last weekend when a crash at Hockenheim allowed fellow four-time champion Hamilton to leapfrog him again at the top of the standings.
The visionary Italian-Canadian executive had already been preparing to hand over control of Fiat Chrysler Automobiles in 2019.
And he subsequently merged Fiat with the troubled US group Chrysler in 2009, transforming the combined entity into a global player that boasted a record performance in 2017.
Marchionne resurrected one of Italy's biggest corporate names and revitalized Chrysler, succeeding where the USA company's two previous owners - Mercedes parent Daimler and private equity group Carberus - failed.
News broke out yesterday that former Ferrari president Sergio Marchionne had died following complications from his shoulder surgery. "He taught us to think differently and to have the courage to change, often in unconventional ways, always acting with a sense of responsibility for the companies and their people", Elkann said.
The health of a CEO is a serious and potentially market-moving matter for employees and shareholders, especially when one is as closely identified with a company's success as Marchionne was.
As Fiat Chrysler heads into what most industry executives and analysts predict will be a hard 2019, the automaker's Italian brands have lost a powerful champion with Marchionne's departure. He brought in other outsiders to key positions and relaunched the iconic 500, which became one of the new Fiat's calling cards as it expanded overseas.
Marchionne had planned to step down as CEO of FCA after the close of 2018.
On Saturday, FCA named Jeep division head Manley, 54, as head of the world's seventh-largest carmaker, saying the Briton would execute a strategy that Marchionne had outlined in June.
A auto fanatic and especially passionate about the luxury vehicle brand Ferrari, Marchionne divided his time between his three homes in Turin, Switzerland and Detroit.
A company veteran who joined Fiat in 1990, Altavilla took charge of the group's struggling European operations in 2012 and returned them to profit three years later. I would like to move forward with the presentation. He had last been seen in public on June 26, at an event in Rome. He noted that his father was a Carabinieri officer and he recognised in the Carabinieri "the same values at the basis of my own education: seriousness, honesty, sense of duty, discipline and spirit of service".
Marchionne is survived by his partner Manuela and sons Alessio and Jonathan.