Apple's recent move to block the Palm Pre syncing with Apple's iTunes music software has had a knock-on effect on Palm's shares.

Shares of Palm have dropped more than 3% on the back of the news after an Apple software update closed the "loophole" that allowed Pre-syncing.

"It also disables devices falsely pretending to be iPods, including the Palm Pre. As we've said before, newer versions of Apple's iTunes software may no longer provide syncing functionality with unsupported digital media players", Reuters quotes an Apple spokesperson as stating.

The aggressive move from Apple, seen as an attempt to protect its long-standing iTunes product from piggy-backing companies, means that Palm will no longer be able to advertise its phone as one that "synchronizes seamlessly with iTunes".

"Palm's media sync works with iTunes 8.2. If Apple chooses to disable media sync in iTunes, it will be a direct blow to their users who will be deprived of a seamless synchronization experience. However, people will have options. They can stay with the iTunes version that works to sync their music on their Pre, they can transfer the music via USB, and there are other third-party applications we can consider", Palm told Pocket-lint.