Palm Inc has escalated its battle with rival Apple Inc, updating the software on its Pre smartphone so that it can again sync with Apple's iTunes media management software.

Palm's move comes after Apple earlier this month closed a loophole in iTunes that had allowed it to sync with Pre. ITunes is designed to work with Apple's iPod and iPhone products.

Palm, whose Pre smartphone was released in June to good reviews and reports of strong early sales, said on Thursday it has released an update to its WebOS software that again allows the Pre to sync with iTunes.

In a blog post announcing the new update, Palm wrote: Oh, and one more thing: Palm webOS 1.1 re-enables Palm media sync. That's right -- you once again can have seamless access to your music, photos and videos from the current version of iTunes (8.2.1).

Apple was not immediately available for comment.

Shares of Apple rose 0.3 percent to $158.31 in early Nasdaq trading, while Palm fell 2.3 percent to $13.83.

(Reporting by Gabriel Madway; Editing by Lisa Von Ahn)