San Francisco - Apple has blocked users of the Palm Pre mobile phone from accessing iTunes, preserving the world's dominant music software as the exclusive domain of its own iPhone.

When Palm launched the Pre in early June it touted the device's ability to sync music, photos and videos with a PC or Mac via iTunes - the only non-Apple mobile device able to do this.

But after warning last month that it would block Palm Pre's access, Apple carried out the threat in a software update to iTunes issued Wednesday, which it said "provides a number of important bug fixes and addresses an issue with verification of Apple devices."

The Palm Pre is one of several competitors to Apple's iPhone, but like the others it falls far behind Apple's hit device in popularity and cachet. In its launch weekend last month, Palm Pre sold an estimated 55,000 units compared to the one million iPhone 3GS units that Apple sold over its launch weekend.(dpa)