AMSTERDAM, June 24 (Reuters) - Apple's App Store rules breach EU tech rules known as the Digital Markets Act (DMA) because they prevent app developers from steering consumers to alternative offers, EU antitrust regulators said on Monday.

The European Commission, which also acts as the EU antitrust and technology regulator, said it had sent its preliminary findings to Apple following an investigation launched in March.

The EU executive said it was also opening an investigation into the iPhone maker over its new contractual requirements for third-party app developers and app stores.

It singled out Apple's three business terms.

"None of these business terms allow developers to freely steer their customers. For example, developers cannot provide pricing information within the app or communicate in any other way with their customers to promote offers available on alternative distribution channels," the EU watchdog said. (Reporting by Foo Yun Chee)