Apple took a challenge against EU regulators to Europe's second-highest court on Monday after they fined it 500 million euros ($587 million) earlier this year for breaching landmark rules aimed at curbing the power of Big Tech.

The European Commission in a decision in April said the iPhone maker's technical and commercial restrictions that prevent app developers from steering users to cheaper deals outside the App Store breached the Digital Markets Act.

Apple, which had previously said it would seek legal redress, filed its lawsuit on Monday, the deadline for doing so.

"Today we filed our appeal because we believe the European Commission's decision - and their unprecedented fine - go far beyond what the law requires," the company said in a statement.

"As our appeal will show, the EC is mandating how we run our store and forcing business terms which are confusing for developers and bad for users. We implemented this to avoid punitive daily fines and will share the facts with the court."

Last month, Apple overhauled its App Store rules to comply with the EU order to scrap its technical and commercial curbs on app developers in order to avoid daily fines of 5% of its average daily worldwide revenue or about 50 million euros per day.

The EU competition watchdog is seeking feedback from app developers before deciding whether to accept the changes or demand more.