The company started declaring quarterly auction results from March to offer users three providers alongside Google. Google and the auction winners will be ordered randomly in the choice screen on a user's device.
In the latest October-December auction, Bing won the rights in 13 countries, Puerto Rico-based PrivacyWall in 22 countries and US-based Info.com got all 31 countries. Other winners included independent search engine DuckDuckGo, Germany's GMX and Russian internet giant Yandex.
DuckDuckGo, which won the auction in eight countries, criticised the process, saying it encouraged bidders to exploit users.
"Google's auction further incentivises search engines to be worse on privacy, to increase ads, and to not donate to good causes, because, if they do those things, then they could afford to bid higher," DuckDuckGo said in a blog post.
A Google spokeswoman said: "the goal is to give all search providers equal opportunity to bid; not to give certain rivals special treatment."
"In developing the choice screen for Europe, we carefully balanced providing users with yet more choice while ensuring that we can continue to invest in developing and maintaining the open-source Android platform for the long-term," she said.