March 1 (Reuters) - Apple's proposed changes for its App Store policies "disregard" the European Union's new competition law for Big Tech firms and amplify its dominance over app developers, a group of more than 30 tech firms and associations, including Spotify, said on Friday.

The move is the latest in an effort led by Spotify Technology against the iPhone maker's App Store policies, which some developers and firms regard as unfair.

"Apple's new terms not only disregard both the spirit and letter of the law, but if left unchanged, make a mockery of the DMA (Digital Markets Act)," the group wrote in a letter to the European Commission.

Apple charges up to 30% annual fee from developers who distribute their apps through the App Store and restricts them to its own payments processing system.

The company in January proposed certain changes ahead of a March 7 deadline to comply with certain conditions of the DMA, a legislation meant to make it easier for European users to move between competing services.

Apple said it would allow alternative app stores on iPhones and an opt-out from using the in-app payments system, but set a "core technology fee" of 50 euro cents per user account per year for developers who sign up for the new regime.

"The new fee structure in the proposed new terms seems designed to maintain and even amplify Apple's exploitation of its dominance over app developers," the letter, also signed by U.S. gaming firm Epic Games and French music streaming service Deezer, said.

Signatories to the letter included European Publishers Council (EPC), which includes chairmen and CEOs of the region's leading media groups.

European Union Commissioner Thierry Breton had said in January Apple could face strong action if changes to its App Store do not meet incoming regulations.

(Reporting by Yuvraj Malik in Bengaluru; Editing by Shilpi Majumdar)