These six unit chiefs run Berkshire Hathaway's key businesses.
Company: Burlington Northern
2009 Revenues: $14.0 billion
A long-term thinker, Rose has expanded the railroad impressively. As the latest addition to Buffett's star roster, he now needs to prove he can thrive in the Berkshire culture.
NEXT: Tony Nicely
Last updated August 02 2010: 6:54 AM ET
Note: Figures for insurance companies are underwriting revenues.