"We've traded publicly [for] 100 years out there," she told "Mad Money" host Jim Cramer on Tuesday. "And the trick to being a company in tech, which is a viciously competitive environment, that's absolutely right, is you've got to keep reinventing. And what IBM is for is for someone who values high value as a company."
At the time of his sale, the Berkshire Hathaway chairman and CEO cited "pretty tough competition" and a changing playing field.
"I don't value IBM the same way that I did 6 years ago when I started buying ... I've revalued it somewhat downward," Buffett told CNBC.
Watch the full segment here:
As of May, Buffett still owned more than 50 million shares in the company.
Rometty defended the way she has chosen to run IBM, saying that divesting some business and building new ones has always been part of the manufacturing giant's operations.
"It is always about moving to where the profit and the value is, and what that does for an investor is that always gives us the ammunition to reinvent ourselves, those profits do, and then with that, continuously raise your dividend," the CEO said.
And as the leader of a company with a nearly 4 percent yield, strong balance sheet and lots of cash on hand, Rometty seemed at peace with Buffett's decision.
"I let every investor speak for themselves, ... and I'm very appreciative of all our investors," she told Cramer.
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