Steve Ballmer Microsoft

Former Microsoft CEO Steve Ballmer told CNBC on Friday that he tried to buy Facebook when it was "itsy-bitsy" for $24 billion.

Ballmer left Microsoft in 2014 and is now the owner of the Los Angeles Clippers and an investor in Twitter.

Facebook fielded a lot of offers in its early days, and Microsoft's interest has been reported in David Kirkpatrick's 2010 book "The Facebook Effect."

"Microsoft [would] acquire a small stake in Facebook at a $15 billion valuation," Kirkpatrick said. "Then, Microsoft would have the option, every six months, to buy another 5 percent of Facebook. A complete takeover of the company would take 5 to 7 years."

When CNBC on Friday asked Ballmer how much Microsoft offered back then, he said, "Oh I think $24 billion when the company was itsy-bitsy and he said no. And I respect that."

Zuckerberg clearly made the right choice. He currently has a net worth of $57 billion and Facebook's market cap is $374 billion.