Unveiled at San Francisco by company CEO Steve Ballmer, the new release features the classic Word, PowerPoint and Excel, but has been rehauled to adapt to devices with touch, stylus and mouse interfaces.
"We are taking bold steps at Microsoft. The new, modern Office will deliver unparalleled productivity and flexibility for both consumers and business customers. It is a cloud service and will fully light-up when paired with Windows 8," Ballmer said in a statement.
The full-fledged suite is expected to be available only next year.
Smartphones and tablet PCs usage at workplaces is on the rise globally and employees are being offered the choice by companies to use applications and data in the cloud.
Cloud computing allows storage of data and access to software on a pay-per-use model, helping companies to cut costs as they do not have to invest in infrastructure.
The new suite makes use of cloud computing and also incorporates Skype, the video-calling service acquired by Microsoft in 2011 for $8.5 billion.
The launch comes at an important time as competitors like Google are making strong inroads into enterprises with productivity solutions, which has been a strong driver for Microsoft.
While the full lineup of offerings and pricing plans will be announced in the fall, Ballmer said three new Office 365 services -- Home Premium, Small Business Premium and ProPlus -- will be available on subscription basis.
In addition, subscribers will receive future rights to version upgrades as well as per-use rights across up to five PCs or Macs and mobile devices, but no timelines were given.