Other competitors in the transportation sector include: Kansas City Southern (KSU), CSX (CSX), and Canadian National Railway (USA) (CNI).

FORBES: Earnings Preview: Union Pacific

Gates is methodically diversifying his wealth: He sells 20 million shares each quarter, reinvests through Cascade Investment in nontech companies, including big stakes in Cox Communications, Canadian National Railway, Republic Services.

FORBES: Source: Microsoft

Each had ten companies on the list, including Biogen Idec (No. 8), Intel (No. 14) and Cisco Systems (No. 20), and Teck Resources (No. 21), Barrick Gold (No. 40), and the Canadian National Railway Company (No. 57), respectively.

FORBES: The World's Most Sustainable Companies