Facebook is reportedly prepping an antitrust lawsuit against Apple focused on its App Store rules

• Facebook is prepping an antitrust lawsuit against Apple, according to The Information.
• The suit reportedly alleges Apple abused its market power by stifling third-party developers in the App Store.
• The companies have traded jabs in the past over anticompetitive practices.

Facebook is readying an antitrust lawsuit against Apple, according to a report from The Information.

Facebook has been preparing the case for months alongside external legal experts, sources told the outlet. The lawsuit specifically alleges that Apple abused its market power by forcing third-party developers, including Facebook, to follow a different set of rules that Apple's branded apps aren't required to follow. For example, Apple forces outside developers to use an in-app payment service instead of their own.

The complaint could also zero in on Apple's practice of barring third-party messenger apps from being the default platform on Apple's products. According to the report, Facebook has discussed possibly inviting other companies to join the potential lawsuit.

In a statement to Insider, a Facebook spokesperson did not confirm the presence of a lawsuit but said "we believe Apple is behaving anti-competitively by using their control of the App Store to benefit their bottom line at the expense of app developers and small businesses."

Apple did not immediately respond to Insider's request for comment.

The news comes as Facebook and Apple, as well as Amazon and Google, remain under antitrust scrutiny from top US officials. Apple CEO Tim Cook and Facebook CEO Mark Zuckerberg were grilled in front of Congress in July as part of an antitrust investigation into online market competition. Both companies face pressure for different reasons: Facebook for its lucrative advertising business and Apple for its App Store policies.

It's rare for two of the world's biggest tech companies to take their grievances against each other to the courtroom, but Facebook and Apple's steaming rivalry goes back years to at least 2014 when CEO Tim Cook took an apparent jab at Facebook's business model, as Insider's Avery Hartman reported.

Read more: The battle between Facebook and Apple over privacy is about more than just ads - it's about the future of how we interact with tech

Most recently, Mark Zuckerberg took a swing at Apple in Facebook's Q4 earnings call, appearing to accuse the company of what could be anticompetitive business practices.

"We are also seeing Apple's business depend more and more on gaining share in apps and services against us and other developers," Zuckerberg said in Wednesday's call. "So Apple has every incentive to use their dominant platform position to interfere with how our apps and other apps work, which they regularly do to preference their own. And this impacts the growth of millions of businesses around the world."

The two have also jousted over which tech giant exploits their users more. In a November letter to privacy nonprofits, Apple accused Facebook of hoovering up "as much data as possible" while showing a "disregard for user privacy." Facebook responded by accusing Apple of abusing its market dominance to "self-preference their own data collection."