Talking to Bloomberg, Gates said it is better to regulate big tech companies as breaking them up will simply result in two companies indulging in bad behaviour.
"I don't know the last time a company was broken up but you have to really think, 'Is that the best thing if there's a way that a company's behaving that you want to get rid of?' Then you should just say, 'Hey, OK, that's a banned behaviour,'" said Gates.
"Splitting a company in two and having two people doing the bad thing, you know that doesn't seem like a solution," he added.
Gates said it was a "pretty narrow set of things" where a break-up would be a suitable solution.
"I was naive about this but that was a long time ago and I didn't realise that as Microsoft gets successful we'd come under scrutiny and we went through our thing back in the 1990s and that's made us more thoughtful about this kind of activity," he said.