(Reuters) -A U.S. lawsuit where Alphabet's Google was ordered on Tuesday to share search data with competitors is just one of the major efforts by U.S. antitrust enforcers to challenge Big Tech companies over their dominance.

Here are the statuses of the U.S. antitrust cases or probes against some of the world's most valuable companies: Alphabet's Google, Meta Platforms ( META ), Apple ( AAPL ), Amazon, Microsoft ( MSFT ) and Nvidia ( NVDA ).

GOOGLE

The internet juggernaut is fighting the U.S. Department of Justice and state enforcers on two fronts. In one case, a judge in Washington ruled the company will have to share data with competitors to open up competition in online search and barred Google from entering exclusive agreements that would prohibit device makers from preinstalling rival products on new devices. Google has already hired a former Obama official to represent it in an appeals process which could take years.

The judge ruled, though, that Google would not have to sell its popular Chrome browser and Android operating system.

While Google will likely get a reprieve from complying with the ruling until the appeal is over, the search landscape has already started to shift, with Google preemptively loosening its deals with device makers and wireless carriers, and Apple ( AAPL ) saying it plans to add search options fueled by artificial intelligence.

Meanwhile, Google is gearing up for a September trial in Alexandria, Virginia, to determine whether it must sell off part of its online advertising technology to make room for new entrants in the field, where it was found to have two illegal monopolies. Google has said it will appeal.

META

The Facebook parent company faced its own antitrust trial this year on the U.S. Federal Trade Commission's bid to unwind Meta's acquisitions of prized assets Instagram and WhatsApp. The agency sought to show Meta strategically bought up emerging apps that it saw as potential Facebook rivals, partly through internal statements like a 2008 email in which CEO Mark Zuckerberg said "it is better to buy than compete."

Meta has said Zuckerberg's past intentions are irrelevant and the case must fail because it depends on a made-up social media market that leaves out ByteDance's TikTok, Alphabet's YouTube and others.

The judge overseeing the case in Washington is unlikely to rule before late 2025.

AMAZON

The online retail giant is battling the FTC and state enforcers in Seattle, where the agency has sued Amazon accusing it of using anti-competitive tactics to maintain dominance among online superstores and marketplaces.

The FTC alleged Amazon.com, which has 1 billion items in its online superstore, was using an algorithm that pushed up prices U.S. households paid by more than $1 billion. Amazon has said in court papers it stopped using the program in 2019. Last year, a judge largely rejected Amazon's bid to dismiss the case. The trial is scheduled for February 2027.

APPLE ( AAPL )

The Justice Department and a coalition of states are suing the maker of the world's most popular smartphone. They say Apple thwarts competition by restricting the makers of apps and third-party devices -- such as smart watches, digital wallets and messaging services -- to keep iPhone users locked in.

Apple's ( AAPL ) bid to dismiss the case was rejected in June. Deadlines for both sides to exchange information in the case stretch into early 2027, and no trial date has yet been set. 

MICROSOFT ( MSFT )

The FTC in 2024 opened a probe into whether the software and cloud computing heavyweight abused its market power in productivity software by imposing punitive licensing terms to prevent customers from moving their data to rival platforms. The FTC has yet to file a case.

NVIDIA ( NVDA )

The Justice Department launched an investigation into the semiconductor company whose highly-sought after chips power artificial intelligence applications and made it the first company in the world to be worth $4 trillion, the Information reported last year. No lawsuit has been filed.