(Reuters) - Apple ( AAPL ) has asked to participate in Google's upcoming U.S. antitrust trial over online search, saying it cannot rely on Google to defend revenue-sharing agreements that send the iPhone maker billions of dollars each year for making Google the default search engine on its Safari browser.

Apple ( AAPL ) does not plan to build its own search engine to compete with Alphabet's Google, whether or not the payments continue, the company's lawyers said in court papers filed in Washington on Monday. Apple ( AAPL ) received an estimated $20 billion from its agreement with Google in 2022 alone.

Apple ( AAPL ) wants to call witnesses to testify at an April trial. Prosecutors will seek to show Google must take several measures, including selling its Chrome web browser and potentially its Android operating system, to restore competition in online search.

"Google can no longer adequately represent Apple's ( AAPL ) interests: Google must now defend against a broad effort to break up its business units," Apple ( AAPL ) said.

The Department of Justice's prosecution of Google is a landmark case that could reshape how users find online information.

Google has proposed to loosen its default agreements with browser developers, mobile-device manufacturers and wireless carriers, but not to end its agreements to share a portion of ad revenue Google generates from search.

A spokesperson for Google declined to comment on Tuesday.