To compete with Google, Microsoft will launch a cloud version of its popular software Office in June called Office 365.

Chief Executive Steve Ballmer gave the release date at a cloud computing conference in Delhi, India, on Thursday. The service will offer Office as a monthly subscription service that will compete with Google Apps, the pay version of the free Google Docs.

"We're pushing hard in the productivity space. We'll launch our Office 365 cloud service, which gives you Lync and Exchange and SharePoint and Office and more as a subscribable service that comes from the cloud," Ballmer said, in a Microsoft transcript of the speech. "That launches in the month of June."

Going to the cloud is a strategic shift at Microsoft that started in full force last year. Microsoft is moving its software products, which used to come in a box and get installed on a PC or corporate server, into the cloud.

In cloud computing, software and data are stored on remote servers run by other companies, and delivered to computers and users via the Internet. Microsoft is competing with Amazon.com and Salesforce.com to gain early customers.

Last June, Microsoft launched a new version of Office called Office 2010. The company also started offering free versions of Word, Excel and PowerPoint called Office Web Apps last year.

The company has already started selling a monthly subscription called Windows Intune that delivers Windows 7 as cloud service.