Spotify confirmed on Friday that it has complained to Apple Inc after the US tech giant rejected an updated app for the Swedish music streaming service on iPhones.

The two companies have gone head to head in the battle for music streaming customers since Apple Music was launched in more than 100 countries last year, and Spotify said the rejection of its revised app for iPhones was causing it “grave harm”. The complaint was in the form of a letter sent by Spotify’s lawyer to Apple this week, technology website Recode reported.

The letter said Apple’s rejection of the revised app raised “serious concerns” under competition law in the United States and Europe. “We cannot stand by as Apple uses the App Store approval process as a weapon to harm competitors,” it said. – (Reuters)