SAN FRANCISCO » New versions of Microsoft’s word processing, spreadsheet and email programs will sport touch-based controls and emphasize Internet storage to reflect an industry-wide shift away from the company’s strengths in desktop and laptop computers.

The new offerings appear designed to help Microsoft retain an important source of revenue as more people access documents from mobile devices. The new Office suite also reflects the fact that people tend to work from multiple computers — perhaps a desktop in the office, a laptop at home and a tablet computer on a train and a smartphone at the doctor’s office.

Like an upcoming redesign of Microsoft’s Windows operating system, the new Office will respond to touch as well as commands delivered on a computer keyboard or mouse.

The addition of touch-based controls will enable Office to extend its franchise into the rapidly growing tablet computer market. Apple dominates that market with the iPad, though Microsoft has plans to compete with its own tablet, called Surface.

The programs will store documents online through Microsoft’s SkyDrive service by default, meaning users will have to change settings to store documents on their own computer. The programs will also remember settings, including where you last left off in a document, as you move locations.

The Internet-based services approach is one Google has been promoting with its own suite of similar programs, threatening Microsoft’s dominance.

“This is the most ambitious release of Office that we have ever done,” CEO Steve Ballmer said Monday in unveiling the new Office in San Francisco.

A preview version of the new Office suite is being made available online at http://office.com/preview. Microsoft Corp. isn’t saying when it will go on sale or what the price will be. Those details will come in the fall.