Lenovo Group Ltd., the world’s No. 3 PC maker, said today that it will start selling versions of its laptop computers preloaded with Linux software from Novell Inc. instead of Microsoft Corp.’s Windows operating system.

The laptops are scheduled to go on sale in the fourth quarter of this year and will be sold to Lenovo’s business customers as well as to consumers.

Lenovo announced its plans at the start of LinuxWorld, an annual conference for IT managers that’s being held in San Francisco this week.

The Linux operating system has been one of the fastest-growing types of software on servers and other kinds of powerful business computers over the past decade.

Last year, Microsoft entered into a business partnership with Novell that includes joint product development on server software. Microsoft also sells Novell products, and both companies agreed to provide patent protections for each other’s customers.

PC makers have been reluctant to embrace Linux, but that view is starting to change.

In May, No. 2 PC maker Dell Inc. began selling three models to U.S. consumers that come preloaded with the Ubuntu version of Linux, which is commercially sponsored by Canonical Ltd.

Dell introduced them after CEO Michael Dell asked customers to post suggestions for new products on the company’s Web site. Linux PCs were overwhelmingly the most-requested item.

Ubuntu founder Mark Shuttleworth, who runs privately held Canonical, which sells service contracts to maintain Ubuntu software, said in an interview last month that he expects Dell to expand its Linux PC program.

He also said that he is in negotiations with other large PC makers that want to introduce models preloaded with Ubuntu.