Google expects to release its Chrome computer operating system in the "late fall", a top executive said on Wednesday, as it aims a competitive strike at rival Microsoft's Windows.

The Chrome system will designed initially to work on laptop PCs, Sundar Pichai, Google's head of the Chrome project told reporters at the Computex PC show.

"We will be selective on how we come to market because we want to deliver a great user experience," he said. "We're thinking on both the hardware and software levels."

Google is seeking to challenge the dominance of Microsoft's Windows operating system, which currently runs on more than 90 per cent of all personal computers currently.

Microsoft on Thursday waved off Google's efforts to develop an open source operating system, saying that software developers would have to create different versions of the same application for different brands.

Pichai disputed that contention, saying the similarity in the base core would mean software companies would not have to develop a new version for Chrome.

"Chrome OS is one of the few future operating systems for which there are already millions of applications that work," Pichai said. "You don't need to redesign Gmail for it to work on Chrome. Facebook does not need to write a new app for Chrome."

Open source software allows tech companies such as Acer to develop their own versions of the software using the skeleton provided by Google to fit their own needs, and its presentation may differ between brands.

The Chrome operating system will be centred around the Web browser, with all software including high-end applications such as those used in photo and video editing housed in external servers known as a cloud.

"We expect a generation of applications, including games, to work inside the browser," Pichai said. – Reuters