Microsoft Corp said on Tuesday it will launch its long-awaited Windows Azure cloud computing system on Jan 1, as it looks to take advantage of the growing interest in internet-based software and services.

Azure, which provides an online platform for software developers to create their own programs, and space for customers to store data, was rolled out for experimentation a year ago.

The service will go fully live at the beginning of next year, Microsoft's chief software architect Ray Ozzie told the company's annual software developers conference on Tuesday.

The first month of the service will be free, and billing will start in February, said Ozzie.

Microsoft is expected to be a big player in the cloud computing market -- broadly the trend toward running software in remote data centers and accessing it over the Internet -- but has lagged behind pioneering rivals such as Inc, which already sells cloud-based storage, and Google Inc, which offers a range of free, online software.

(Reporting by Bill Rigby)