A billionaire who backed Jeff Bezos and Larry Page said not investing in 'slightly crazy' Elon Musk was 'probably the worst investment decision of all time'

• John Doerr said he missed an opportunity to invest in Tesla in 2007.

• The venture capitalist chose to invest in a competitor that later went bankrupt instead.

• Doerr has been known for backing several key companies, including Amazon, Google, and Twitter.

Billionaire investor John Doerr said passing up on an opportunity to invest in Tesla in 2007 is one of his biggest regrets.

"The conventional wisdom was that venture capitalists thought not to invest in electric vehicle companies and not new car companies at all," Doerr, the chairman of venture capitalist firm Kleiner Perkins, told Bloomberg Television.

"We had the choice of backing a brilliant car designer by the name of Henrik Fisker or an ambitious, slightly crazy entrepreneur by the name of Elon Musk with Tesla and we made the wrong decision," he added.

In 2008, Kleiner Perkins invested over $10 million in Fisker Automotive. About five years later the company filed for bankruptcy. Henrik Fisker started another EV company named Fisker Inc. in 2016 using the same logo and trademarks. Since, the company has gone public on the New York Stock Exchange, but has lagged far behind Tesla.

In 2007, Tesla was still a fledgling company in transition, its cofounder Martin Eberhard was in process of stepping down as CEO, and Musk didn't take over the role of chief executive until the following year. The company didn't produce its first car until 2008, nearly five years after the company was founded. Today, the electric-car maker is valued at almost $1 trillion.

"That's probably the worst investment decision of all time," Doerr said on "Bloomberg Wealth with David Rubenstein." "I don't obsess on these [regrets], but I won't ever forget," the billionaire added.