Microsoft on Wednesday courted the favor of antitrust regulators scrutinizing its plan to buy video game maker Activision Blizzard, promising that any app store it builds will treat developers fairly.

Microsoft president Brad Smith laid out a set of “Open App Store Principles” that will apply to the store it runs for Windows-powered computers and “the next-generation marketplaces we will build for games.”

“We have developed these principles in part to address Microsoft’s growing role and responsibility as we start the process of seeking regulatory approval in capitals around the world for our acquisition of Activision Blizzard,” Smith said in a statement.

Microsoft’s $69 billion deal to buy video game powerhouse Activision Blizzard needs to pass muster with regulators in Europe and the United States intent on reining in tech titans.

After the merger plans were announced last month, analysts told AFP the deal would certainly be scrutinized, but likely less intensely than would an acquisition by Amazon, Google, or Facebook-parent Meta.

Microsoft appeared to be trying to differentiate itself from Apple and Google, who have been accused of tightly controling their respective app stores and taking too big a bite out of revenue brought in by developers.

Principles outlined by Microsoft included allowing all developers access to its app store and not requiring them to use the technology firm’s payment system for in-app transactions.

All apps in a Microsoft shop will be treated equally, according to Smith.

“We want to encourage more innovation and investment in content creation and fewer constraints on distribution,” he said.

“The world needs open app markets, and this requires open app stores.”

Tech giants have come under fire from multiple fronts for app store controls.

In January, Apple was fined five million euros ($5.6 million) by the Dutch consumer watchdog for failing to allow dating app operators to choose payment options other than the Apple Pay system in its Dutch App Store.

In November, a US federal court ordered Apple to loosen control of its App Store payment options after a legal clash with Fortnite creator Epic Games, which had accused the iPhone maker of operating a monopoly in its shop for digital goods or services.

The US judge, however, said Epic had failed to prove that antitrust violations had taken place.

Epic Games is locked in bitter legal battles with Apple and Google, whose operating systems run nearly all the smartphones in the world.

Both companies charge what they deem appropriate fees on transactions made on Apple’s App Store and Google Play.

But app makers have become increasingly furious in recent years over the cut taken by the tech giants.