Steve Ballmer, the former chief executive officer of Microsoft (MSFT) Corp., became the company’s biggest individual shareholder yesterday after Bill Gates sold 4.6 million shares of the world’s largest software maker.

The 58-year-old, who retired Feb. 4 after serving 33 years at the Redmond, Washington-based company, owns 333.2 million shares of Microsoft, 3.1 million more than Gates. Ballmer has collected about $3.4 billion selling shares since the company’s 1986 initial public offering, and has a net worth of $18.8 billion, according to the Bloomberg Billionaires Index. Steve Ballmer Usurps Bill Gates As Microsoft's Biggest Individual Shareholder [bloomberg.com]