Google today introduced a version of its Apps suite offering guaranteed uptime, IT management tools, increased email storage and integration with Docs & Spreadsheets as well as BlackBerry support for Gmail.

The search giant is pushing further into the communication and collaboration applications market with the major Google Apps upgrade, which analysts say could soon become a real competitor to Microsoft Office.

With a cost of $50 (£25.58) per user per year, Google Apps Premier Edition becomes the third and most sophisticated version of the suite, launched in August with the free Standard Edition and Education Edition versions. Like the original editions, Premier will have services like Gmail web mail, Calendar shared scheduling and Talk instant messaging.

Those that sign up for Google's Premier edition will get 10GB of email storage per user, compared to 2GB in the Standard edition, a 99.9% uptime guarantee and phone support for IT administrators. It also includes application programming interfaces (APIs) to integrate the suite with business applications and data.

The Standard and Education editions are also getting enhanced with the Docs & Spreadsheets integration and the BlackBerry support for Gmail.

Until today the suite was called Google Apps for Your Domain, because organisations offer these Google hosted services using their own internet domain and branding. Over 100,000 small businesses use the Standard edition and hundreds of universities use the Education edition.

Google Apps represents a new, hosted approach for the cost and maintenance benefits it offers to productivity suites in a market ruled by Office, which is mostly desktop software.

Forrester Research isn't telling enterprises to drop Office, but it is recommending that CIOs give Google Apps a serious look, in large measure because Office's price is high, said analyst Erica Driver. Today, Google Apps is a cheaper alternative to the core Office applications, but eventually it could be a replacement option, as Google grows its capabilities and CIOs get more comfortable with software as a service, she said. "Microsoft has a chance to respond, but this changes the game," Driver said.

"This is a very big step forward for Google Apps," said Dave Girouard, vice president and general manager of Google's enterprise unit. The company plans to add several more applications to the suite before the year is out, and the JotSpot wiki service is a likely candidate, he said.

Google also plans to create an ecosystem of partners and developers around Google Apps.