Formula One CEO Chase Carey has led racing's tributes to former Ferrari president Sergio Marchionne, who died on Wednesday.
Marchionne, who was 66, died after complications from surgery in Zurich.
"We are deeply saddened by the passing of Sergio Marchionne," said Carey. "He was a great leader of not just Formula 1 and the automobile world, but the business world overall.
"He led with great passion, energy and insight, and inspired all around him. His contributions to Formula 1 are immeasurable. He was also a true friend to all of us and he will be deeply missed. At this difficult time we extend our deepest sympathies to his family, friends and colleagues."
Marchionne, who was Italian and Canadian, replaced Luca di Montezemolo at the head of Ferrari in 2014 — with the famous Italian scuderia a fading force in the sport.
Ferrari was the most successful team in F1 but won the last of its 16 constructors' titles in 2008.
Under Marchionne's leadership, Ferrari returned to title-contending form. It has won four of the 11 races to date in 2018 and is challenging for both the drivers' and constructors' titles.
Sebastian Vettel finished runner-up to Lewis Hamilton last year and is currently second, 18 points behind the Mercedes driver.
"This is a sad day for all of us in F1. We have a lost a huge supporter of our sport, a fierce competitor, an ally and a friend," said Mercedes team principal Toto Wolff.
"Our heartfelt sympathies are with Sergio's family and all at ScuderiaFerrari at this difficult time."
Many of the other teams also expressed their sympathies on Twitter, ahead of this weekend's Hungarian Grand Prix.
British team Williams posted on Twitter: "We are very saddened to hear of the passing of Sergio Marchionne. On behalf of all at Williams, we would like to express our condolences to Sergio's family, friends and ScuderiaFerrari."
FCA chairman John Elkann — a grandson of the late Gianni Agnelli, the longtime Fiat dynasty chieftain — had been named the new Ferrari chairman on Saturday after an emergency board meeting of Fiat Chrysler Automobiles.
Marchionne was also the CEO of FCA and engineered two long-shot corporate turnarounds to save both Fiat and Chrysler from near-certain failure, building the dysfunctional companies into the world's seventh-largest automaker, Fiat Chrysler Automobiles.
"It is with great sadness that I learned that Sergio Marchionne tragically and unexpectedly passed away," said Jean Todt, president of motor sport's governing body FIA. "Sergio achieved a colossal amount for the automotive industry and motor sport worldwide.
"He dedicated himself fully to turn around the FIAT-Chrysler group and put all his energy to bring Scuderia Ferrari back to the top. He was an endearing, upstanding and brave man, an unconventional and visionary leader ...His death is a considerable loss."