Apple wants to join the antitrust case against Google, and it has explained why it doesn't want to create its own rival search engine.

Apple 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.

A court filing in the Google monopoly case reveals Apple's lack of appetite for building a search engine or entering the search text ad market.

In a US federal court declaration, Apple SVP of Services Eddy Cue outlines why the company doesn't want to take on Google.

Apple is seeking to defend its deal with Google, which provides revenue sharing through Search. This comes after the DOJ threatened to break up Google's business after a court found that it holds an illegal monopoly.