Apple will open its tap-and-go mobile payments system to rivals, EU antitrust regulators said on Thursday, ending a four-year long investigation that could have resulted in a hefty fine for the iPhone maker.

Apple's decision to settle the EU antitrust probe marks a rare move by the company which has pushed back against the EU competition watchdog scrutinising its business practices. It currently faces three investigations under the Digital Markets Act (DMA) over its business practices.

The European Commission, which acts as the EU antitrust enforcer, said Apple's offer would be valid for 10 years. More than 3,000 banks and issuers in Europe offer Apple Pay.

"From now on, competitors will be able to effectively compete with Apple Pay for mobile payments with the iPhone in shops. So consumers will have a wider range of safe and innovative mobile wallets to choose from," EU antitrust chief Margrethe Vestager said.

Apple's tap-and-go technology called near-field communication, or NFC, allows for contactless payments with mobile wallets. It will now allow developers to access its NFC to pre-build payment apps for rival mobile vallet providers.

Apple said its offer would give European developers an option to enable tap-and-go payments for car keys, closed loop transit, corporate badges, home keys, hotel keys, merchant loyalty/rewards, and event tickets from within their iOS apps.

The EU competition enforcer had two years ago charged Apple with hindering competition for its Apple Pay mobile wallet by blocking rival app developers from accessing its tap-and-go technology.

The company in January offered to settle the case that would stave off a fine and a finding of wrongdoing.

Apple was slapped with a 1.84 billion-euro fine in March, its first EU antitrust penalty, for thwarting competition from Spotify and other music streaming rivals via restrictions on its App Store.