Google Inc. is paying Apple Inc. a hefty fee to keep its search bar on the iPhone.

Apple received $1 billion from its rival in 2014, according to a transcript of court proceedings from Oracle Corp.’s copyright lawsuit against Google. The search engine giant has an agreement with Apple that gives the iPhone maker a percentage of the revenue Google generates through the Apple device, an attorney for Oracle said at a Jan. 14 hearing in federal court.

Rumors about how much Google pays Apple to be on the iPhone have circulated for years, but the companies have never publicly disclosed it. The revenue-sharing agreement reveals the lengths Google must go to keep people using its search tool on mobile devices.

It also shows how Apple benefits financially from Google’s advertising-based business model that Apple CEO Tim Cook has criticized as an intrusion of privacy.

Oracle has been fighting Google since 2010 over claims that the search engine company used its Java software without paying for it to develop Android. The damages Oracle now seeks may exceed $1 billion since it expanded its claims to cover newer Android versions.