"They have this incredible, amazing, dare I say monopoly that we are the only person left on the planet trying to compete with," he said.
Microsoft's Bing service has grown to a 17.9 percent share of the search market in the United States, but still way behind Google at 67 percent. Most of Bing's gains have come from losses at other rival search engines other than Google.
"If we have exactly the same quality of algorithms, but a lot less scale in search advertising, we will get less revenue per search than Google does, which means they have more money to pay for distribution on Samsung devices, or Apple," Ballmer said, reports the Verge.
He then went on to explain that he believes the competition authorities may have a role to play.
"I do believe that Google's practices are worthy of discussion with competition authority, and we have certainly discussed them with competition authorities," said Ballmer. "I don't think their practices are getting less meritorious of discussion."