Microsoft is expected to launch Office 365, a cloud version of Office, on June 28 at a media event in New York City.

Microsoft sent media invitation to a rollout event for Office 365, scheduled on June 28 at Skylight Soho, the same studio that hosted Microsoft Windows 7 launch in 2009.

There, CEO Steve Ballmer will speak about Office 365, Microsoft's next generation cloud productivity service, aimed at providing a comprehensive and streamlined set of services.

Office 365 provides Office Web Apps, lightweight online versions of Word, Excel and PowerPoint, with unified communications software Lync and collaboration software SharePoint. The cloud-based service offers several levels of packages in the form of an online monthly subscription. The entry-level package for Small Businesses provides Office Web Apps, Exchange, SharePoint and Lync online with an external website for $6 per user. Office 365 for Enterprise will include email, voicemail, enterprise social networking, instant messaging, web portals, extranets, voice conferencing and videoconferencing for $24 per user. Targeted at larger businesses, the Enterprise package includes pay-as-you-go access to Office Professional Plus.

The software and data will be stored in Microsoft's data centers accessible online.

Office 365 is mainly targeted at small businesses that may not want to manage their own servers for email and other software, as it will allow users to get to their data from virtually anywhere on desktops, laptops, and mobile devices.

While small businesses may be able to upgrade to the cloud service quickly, larger enterprises may move gradually and opt to use a hybrid of cloud storage and in-house storage. Office 365 will allow them to deploy the latest Microsoft Office software whether it's on the desktop, online or the cloud.

Ballmer said Microsoft is aggressive in the cloud market - We're pushing hard in the productivity space.

The name Office 365 will replace the service called Business Productivity Online Standard Suite (BPOS).