A new version of the Firefox Web browser is scheduled for release Tuesday with improvements in security, speed and design.

Many of the enhancements in Firefox 3 involve bookmarks. The new version lets Web surfers add keywords, or tags, to sort bookmarks by topic. A new "Places" feature lets users quickly access sites they recently bookmarked or tagged and pages they visit frequently but haven"t bookmarked.

There's also a new star button for easily adding sites to your bookmark list - similar to what's already available on Microsoft's Internet Explorer 7 browser.

Other new features include the ability to resume downloads midway if the connection is interrupted and an updated password manager that doesn't disrupt the log-in process.

In a nod to the growing use of Web-based e-mail, the browser can be set to launch Yahoo's service when clicking a "mailto" link in a Web page, the ones you might come across clicking on a name or a "contact us" link. Previously such links could only open a standalone, desktop e-mail program.

Yahoo is the only Web service initially supported. To use rivals like Google's Gmail and Microsoft's Hotmail, developers of those services will have to enable that capability first.

Firefox also will start blocking rather than simply warning about sites known to engage in "phishing" scams that try to trick users into revealing passwords and other sensitive information. The new version adds protection from sites known to distribute viruses and other malicious software.

The list of suspicious sites come from Google Inc. and StopBadware.org, a project headed by legal scholars at Harvard and Oxford universities.

Security researchers who need access to problem sites can manually turn the feature off.

Firefox 3 also offers speed and design improvements - the back button is now larger than the forward button, for instance, because people tend to return to a previous page more often, said Mike Schroepfer, the project"s vice president of engineering.

Firefox is the No. 2 Web browser behind Microsoft's Internet Explorer. It comes from Mozilla, an open-source community in which thousands of people, mostly volunteers, collectively develop free products.

Mozilla has been developing Firefox 3 for nearly three years and has been publicly testing it since November for Windows, Mac and Linux computers.

Its supporters are organizing launch parties around the world next week, and Mozilla is trying to set a world record for most software downloads in a 24-hour period.

Microsoft is currently testing Internet Explorer 8, while Opera Software ASA released Opera 9.5 on Thursday.