Applications to let users watch YouTube videos will not be pre-installed on the next generation of iPhones, iPads and iPod devices, in another sign of mounting rivalry between Apple and Google.

People will still be able to watch YouTube videos on Apple's globally popular products by linking to the service through a Web browser, but will not have the viewer software architecture pre-loaded in the unit.

Google is expected to design a feature-rich YouTube application for Apple's online App Store as an alternative.

"We are working with Apple to ensure we have the best possible YouTube experience for iOS users," a YouTube spokesman told AFP, referring to the operating system for Apple mobile devices.

The change came as competition between Apple and YouTube parent Google intensified and relations between the California companies grow ever colder.

Google is the titan behind Android software powering smartphones and tablets challenging Apple in the booming mobile market.

Apple recently booted Google Maps software from its gadgets, replacing it with a custom mapping program.

Apple tailored a YouTube application for iOS under terms of a license that recently expired. It was unclear on Tuesday why the companies didn't renew the license.

A YouTube icon had been among those that automatically appeared on home screens of iPhones, iPads and iPod touch devices from the moment they were first powered up.

Next-generation iOS 6 software is due for release in the coming months, probably with a new version of the iPhone.

Google in June took the web browser battle to iPads and iPhones with the release of Chrome software for popular Apple devices built with Safari online surfing programs at heart.

Safari remains the default browser used in Apple gadgets and the "engine" that Chrome or other web-surfing applications has to rely on.

Google share price shed a few cents to $642.78 during Nasdaq trading on Tuesday and Apple stock slid slightly to $622.23.