Bob Dudley is not one to wear his disappointment on his sleeve. Even as a kid, "Bobby" as he was then known "was completely unflappable," remembers Charles Brent, Dudley's hometown friend in southern Mississippi in the 1960s. If he tried out for a sports team and got cut, he kept his emotions in check. "Nothing got him upset," said Brent, now a neurosurgeon. "He was often on the bad end of an injustice - where someone was selected instead of him. I never saw him get angry or raise his voice. Or disappointed." Nearly four decades later Bob, no longer Bobby, displayed a similar lack of chagrin when Tony Hayward was selected to become chief executive of oil behemoth BP Plc in 2007, even though many deemed Dudley well - qualified to replace outgoing boss John Browne.

"He was still happy to serve the company as he could," said Dr. Angel Cabrera, president of the Thunderbird School of Global Management, a friend of Dudley's. "There was no acrimony between them."

"He's not the stereotypical aggressive, know-it all CEO type of guy," Cabrera added. "He's a humble man."