America Online Inc. on Tuesday made available in beta a standalone browser that includes desktop search, a feature already offered by rivals Google Inc., Microsoft Corp. and Yahoo Inc.

The AOL Browser is separate from the Netscape browser AOL is also testing. The latter browser does not include desktop search, but allows users to switch from the Mozilla rendering engine to Internet Explorer with the click of a button.

The new AOL Browser, which is available for testing by AOL members and subscribers of the AOL Instant Messenger service, includes tabbed browsing that enables a person to quickly switch back and forth among multiple websites without launching a new browser. The feature is also available in the popular, open-source Firefox browser.

The AOL Browser also provides a privacy button that lets users clear their Internet history, cookies and caches.

But desktop search is the key feature in the new browser, because it has become an area of fierce competition with rivals Google, Microsoft, and Yahoo.

All three competitors have released beta software that can be downloaded to the desktop and used to search files in a person's PC, as well as the web. The tools are viewed as important among search companies because people often begin shopping on the web with a search engine.

AOL, based in Dulles, Va., declined to provide a timetable for when the browser would be generally available.