Warren Buffett And IBM: Berkshire Hathaway Accumulates 5.5 Percent Stake In Tech Company

Warren Buffett announced on CNBC's Squawk Box Monday that his company Berkshire Hathaway had purchased $10.7 billion worth of IBM shares since March 2011 -- good for a 5.5 percent stake in the company,

Buffett, who Forbes labels the third-richest man in the world, is known for making surprise investments. The IBM bet is especially noteworthy, however, because of Buffett's history of avoiding tech companies. His reason for remaining skeptical all these years? He often doesn't "understand" what the companies themselves do, CNBC reports.

But after reading IBM's 2010 annual report "through a different lens," Buffett said he'd changed his mind.

"I don't think there is any big company that I can think of, that has done a better job of laying out where they're going to go and then having gone there," Buffett told CNBC. "They laid out a road map. I should have paid more attention to it five years ago."

In particular, Buffett praised former CEO Lou Gerstner for saving the company from bankruptcy, and current CEO Sam Palmisano, who he said has "delivered big-time," according to Fortune.

IBM has recently benefited from an emphasis on higher-margin businesses such as data-analysis services, the Wall Street Journal reports. The positive public reception of Watson, a super-computer who bested human competitors on the game show Jeopardy, also gave the company extensive positive press. Indeed, Watson eventually led the company to an Internet achievement award: the Webby for "Person" Of The Year.

This isn't the only high-profile investment Buffett's made recently. In August, Buffett invested $5 billion in Bank of America, a company plagued by negative publicity after a plan to charge customers $5 fee to use debit cards caused a national uproar. Still, Buffett told CNBC on Monday that the BofA CEO Brian Moynihan is following a "very logical path" to get the bank back on track.

Outside of his Berkshire Hathaway duties, Warren Buffett has personally taken on the issue of tax rates for America's richest taxpayers, writing in August that "while most Americans struggle to make ends meet, we mega-rich continue to get our extraordinary tax breaks." President Obama subsequently named a proposed millionaire's tax the "Buffett rule."

As of 12:15pm, IBM's stock was up .37 percent for the day, according to Google Finance.

Here are ten other big moments in Warren Buffett's career: