PARIS (Reuters) - Contributions from wireless companies to the Linux operating system have increased rapidly, underlining the success of the open source software platform in smartphones, a report from the Linux Foundation said.

The report, to be unveiled later on Wednesday, shows the role of traditional top contributors - Red Hat, Novell and IBM -- is slightly decreasing, while companies with a strong mobile Linux focus are becoming increasingly important for the development of the platform.

With the success of Google’s free Linux-based Android platform, Linux has become a key force in the smartphone software market. Google aims to copy its success in desktop search to the fast-emerging mobile Internet space.

All top smartphone makers, excluding Nokia and Apple, use Android in their flagship phones.

Earlier this year Intel and Nokia, the world’s largest smartphone maker by volumes, merged their mobile Linux versions into MeeGo, which has reached consumers through one small tablet manufacturer. But the bigger rollout from Nokia itself is expected next year.

Intel has passed Novell and IBM to become the second largest contributor to Linux, while Nokia has risen to the No. 5 spot.

Linux is the most popular type of free, or so-called open source, computer operating system which is available to the public to be used, revised and shared.

The report showed that more than 70 percent of contributions are from developers who are getting paid for their Linux development from corporations who hope to benefit from better software in their core business.

Linux suppliers earn money selling improvements and technical services, and Linux competes directly with Microsoft, which charges for its Windows software and opposes freely sharing its code.