Google entices people to search by promising links to the best that the web has to offer. But research released Monday, led by top academics but paid for by one of Google’s rivals, suggests that Google sometimes alters results to play up its own content despite people’s preferences.

In the study, researchers from Harvard and Columbia presented 2,690 web users with two versions of Google. One version showed search results for local businesses as users usually see them, with links to the businesses along with ratings as posted to a Google site. The other version showed links to businesses along with ratings from rival sites like Yelp, the online review website, which paid for the study.

The people studied were 45 percent more likely to click on links if Yelp and other competitors were included — a sign, researchers say, that users prefer more diverse search results.

The study could renew calls for government regulators — in particular, the Federal Trade Commission — to reopen an investigation into Google for unfairly promoting its own services. The results may also provide new ammunition to officials in Europe who have accused the company of antitrust violations.