Lenovo Group Ltd, the No. 3 personal computer maker, said on Monday it would introduce a broad line of Linux laptops, the strongest endorsement to date of the open-source software by a major PC maker.

The Linux operating system, which competes with Microsoft Corp's market-dominating Windows, has been one of the fastest-growing types of software used on servers and other types of powerful business computers over the past decade.

But until this year, the world's top PC makers have held back on embracing Linux. Windows still sits on more than 90 percent of PCs in the world.

Lenovo said it would offer a wide selection of low- to high-end machines be loaded with Linux software from Novell Inc.

The company has projected Linux PCs could account for 5 percent of its laptop shipments within a few years, said Raj Aggarwal, product manager for Lenovo's ThinkPad laptops.

He said demand for Linux PCs has been on the rise this year, particularly in the education sector, government and emerging markets.

Lenovo's announcement comes three months after the world's second-largest PC maker, Dell Inc, started mass marketing three PC models loaded with the Ubuntu version of Linux, allowing customers to choose it over Windows.

Dell introduced the Linux PCs after Chief Executive Michael Dell asked customers to post suggestions for new products on the company's Web site. Linux PCs were the most-requested item.

So far, Dell and Lenovo are the biggest PC makers to embrace Linux. Market leader Hewlett-Packard Co does not mass produce machines with the software.

"We're waiting for the Linux desktop market to take off," said Laura DiDio, a PC industry analyst with Yankee Group.

The Lenovo laptops are slated to go on sale worldwide in the fourth quarter. The company announced its plans at the start of LinuxWorld, an annual conference being held in San Francisco this week.

Lenovo declined to discuss pricing or which languages Novell's Suse Linux operating system would be available in.

Linux is available in hundreds of versions, for a wide variety of electronic devices, from cell phones to mainframe computers. The bulk of those versions are free.

Novell and Red Hat Inc develop versions for businesses, profiting by selling services such as technical support.

Last year, Microsoft entered into a partnership with Novell focused on server products that includes joint product development. Microsoft's salesforce resells Novell software and both companies provide patent protections for each other's customers.

Aggarwal said Lenovo held off on launching a Linux line until it could provide customers adequate support, offering them tools to integrate their PCs into computer networks.

Businesses that buy the Linux laptops will be able to obtain security software from Novell and programs to remotely manage them from their data centers. Novell will provide regular software updates.

The current version of the Novell operating system also has an improved user interface and comes with a package of free software programs, Aggarwal said.

They include the Firefox Internet browser along with OpenOffice, which competes with Microsoft Office programs such as Word, Excel and PowerPoint. OpenOffice produces documents that are compatible with their Microsoft counterparts.

Microsoft was not available to comment.