Microsoft Word running inside a Web browser.

LOS ANGELES – After dragging its feet for years, Microsoft says it plans to offer Web-based versions of its Office programs that let people create and edit documents inside a browser.

The surprise move, announced here this morning, is a sharp change for one of the Redmond company’s oldest and most profitable franchises. Traditional versions of Microsoft Word, Excel and other programs dominate the market, and Microsoft has been reluctant to offer functional online counterparts -- even as Google and other rivals have beaten it to the punch.

It’s part of Microsoft’s broader move toward online services, coming a day after the company announced plans for a new “cloud computing” platform, Windows Azure, that will let software developers create and deliver programs over the Internet from Microsoft’s data centers.

Taken together, the moves reflect a new era for Microsoft under the leadership of Ray Ozzie, the online services guru who has replaced Bill Gates as the company’s chief software architect.

However, the company says it’s not looking to abandon its traditional software businesses. Microsoft describes the Web-based Office applications as “lightweight” versions that aim to complement the standard Office programs without replacing them.

Microsoft says it will offer Word, Excel, PowerPoint and the OneNote note-taking application as Web applications. The company isn’t say when final versions will be made available in final form, except that they will come with the next wave of Office programs. Microsoft says it expects to conduct a private technical preview of the Office Web applications this fall.

An existing Microsoft offering, Office Live Workspace, offers online document sharing and collaboration, but without full-fledged authoring and editing capabilities.

The Web-based Office applications will come with an on-screen interface reminiscent of their PC-based counterparts, with a variation of the “ribbon” navigational menu that was introduced in the most-recent release of the traditional Office programs.

The company isn’t disclosing pricing or other specifics. The Web-based Office programs will be available to consumers through the existing Office Live service, which offers programs and services under both advertising- and subscription-based models. Microsoft says it will offer the applications to businesses through subscriptions and volume licensing agreements.

The programs are expected to be demonstrated this morning at the company’s Professional Developers Conference here. Also at the conference, Microsoft is giving the first detailed look at Windows 7, the next version of the company’s flagship PC operating system.

The Web-based Office applications will come with an on-screen interface reminiscent of their PC-based counterparts, with a variation of the “ribbon” navigational menu that was introduced in the most-recent release of the traditional Office programs. 

The company isn’t disclosing pricing or other specifics. The Web-based Office programs will be available to consumers through the existing Office Live service, which offers programs and services under both advertising- and subscription-based models. Microsoft says it will offer the applications to businesses through subscriptions and volume licensing agreements.

The programs are expected to be demonstrated this morning at the company’s Professional Developers Conference here. Also at the conference, Microsoft is giving the first detailed look at Windows 7, the next version of the company’s flagship PC operating system.