Apple on Thursday said it is distributing the latest version of the Safari Web browser to Windows users through Apple Software Update, a move that reflects a more aggressive attempt to grab market share from Microsoft Internet Explorer.

Apple uses the update mechanism for Windows for distributing the latest versions of its iTunes music store and for the QuickTime video player, which is a foundation technology for iTunes. With the release of Safari 3.1 this week, Apple also started offering Windows users the option of installing the browser upgrade. Software Update is also used to update Apple software in Mac computers.

"We are using Software Update to make it easy and convenient for both Mac and Windows users to get the latest Safari update from Apple," company spokesman Bill Evans said in an emailed statement.

As of February, IE had 74.9% of the browser market in terms of usage, followed by Mozilla Firefox, 17.3%; and Safari, 5.7%, according to Web site analysis company Net Applications.

By shipping Safari via Software Update, Apple is taking a more aggressive approach to distributing its browser within Microsoft's home turf. In releasing Safari 3.1, Apple claimed its browser loads Web pages 1.9 times faster than IE 7 and 1.7 times faster than Firefox 2. Such claims are not unusual among vendors comparing products to rivals'.

Among the key improvements in the latest version of Safari, which is available at no charge, is support for additional Web standards. On that front, the upgrade supports new video and audio tags in HTML 5, and animations created through the use of cascading style sheets. The browser also supports CSS Web fonts.

Microsoft this month said it would configure the default settings in the upcoming IE 8 to render content using methods that give a top priority to Web standards interoperability. In choosing to favor standards, Microsoft recognized a "concrete benefit to Web designers if all vendors give priority to interoperability around commonly accepted standards as they evolve," Ray Ozzie, chief software architect for Microsoft, said in a statement.