Google Inc. plans to introduce its own Web browser, the latest twist in its battle with Microsoft Corp. over key Internet technologies.

In a posting on a company site Monday, Google indicated that a version of the software, called Chrome, would be available for download on Tuesday. It said the software is designed to make it faster to browse the Web and easier to run applications without downloading software to a computer. The product will be offered on an open-source basis, meaning others can modify the software code.

Internet Browser Web Wars

The Google browser takes direct aim at Microsoft Corp.’s Internet Explorer, which is by far the most widely used program for viewing Internet sites. The two companies already compete in Internet search engines, where Google holds a wide lead. Google has also developed Web-based alternatives to Microsoft’s popular Word, Excel and PowerPoint programs.

While many people pay little attention to which browser they use, the choice makes a big difference to software companies. They can use the precious screen real estate to promote their own Web services. Moreover, they can tailor their browsers to ensure compatibility with their other products.

Google executives have expressed concern that existing browsers might fail to support the sort of new Web-based applications they want to develop as they seek to expand the company’s influence beyond search. By building its own Web-browsing software, Google is ensuring that it will have a platform for its Internet services that needn’t conform to other companies’ standards.

News of the Google project spread after an unconventional leak by the company itself. Google Blogoscoped, a blog that follows the company, reported Monday that Google had sent it a comic book outlining the specifications of the browser.

“We realized that the web had evolved from mainly simple text pages to rich, interactive applications and that we needed to completely rethink the browser,” wrote Sundar Pichai, a Google vice president of product management, on the company site. “What we really needed was not just a browser, but also a modern platform for web pages and applications, and that’s what we set out to build.”

Danny Sullivan, editor in chief of Internet news and analysis site Search Engine Land, said Google’s decision shows how the browser is competing with the traditional operating system as an important platform for software development. He predicted that Google will encourage people to adopt Chrome by releasing some products and updates for Chrome users first, while continuing to support other browsers.

Persuading Consumers

Google may nonetheless have trouble persuading consumers to download its browser. Many people find it easier to use the browser that comes loaded on their computer, which is typically Microsoft’s Internet Explorer on computers that run the Windows operating system.

Dean Hachamovitch, a Microsoft executive who oversees Explorer, expressed confidence that consumers would continue to use the browser. He said Explorer “puts the services [users] want right at their fingertips, respects their personal choices about how they want to browse and, more than any other browsing technology, puts them in control of their personal data online.”

Mr. Sullivan said Google hasn’t had much success getting people to download its software, with the exception of mapping software Google Earth. “Just because Google has a browser out there, it doesn’t mean everyone is going to use it,” he said.

The browser has been viewed as a strategic weapon in high-tech circles since the mid-1990s, after Netscape Communications turned its browser into a fixture on many personal computers. Microsoft viewed that product as a threat that could set a new standard for software development, setting in motion a series of tactics that triggered the Justice Department’s high-profile antitrust investigation of Microsoft.

In recent years, the Mozilla Foundation’s Firefox browser — a descendent of Netscape’s Communicator product — has gained popularity as an alternative to Internet Explorer. Firefox holds nearly 20% of the market, compared with about 72% for Explorer, according to Net Applications, a company that tracks the sector.

More recently, the browser has been seen as a lever in the battle over Internet search. Browsers include windows, or toolbars, that can be used to directly access a search engine, a program for finding information or sites on the Internet. Microsoft’s Internet Explorer browser comes preset with a toolbar for Microsoft’s search engine, though it can be reset to link to Google, Yahoo or other search engines.

That default setting, and how to change it, has been a contentious issue between Google and Microsoft in recent years. Google has claimed to regulators that Microsoft’s domination of the browser market could give it an undue influence over search-engine use. Microsoft, meanwhile, has reworked its browser to make it easier for people to reset to competing search engines.

Google has been working on the product for about two years, according to one person familiar with the matter. The introduction of Internet Explorer 7 in October 2006 added more urgency to the effort, as Google grew concerned that the new version would make it easier for Microsoft to route users to Microsoft’s own search service, this person said.

If people use the Google browser, the company could glean more information about what consumers are doing online, analysts say. Google could find that information useful, they say, in better targeting ads to individual users and conceiving new products. Google already knows a lot about online habits thanks to its domination of the search-engine market and Internet advertising.

Problems for Mozilla

Chrome could create problems for the Mozilla Foundation, the nonprofit organization that builds Firefox. Google has been a key partner for Mozilla, at times providing engineering expertise and paying for a spot as the default search service embedded in Firefox. Google and Mozilla last week renewed their agreement, which was set to expire in November, extending it until 2011.

John Lilly, Mozilla’s chief executive, conceded that Chrome will increase competition in browsers, which also include Apple Inc.’s Safari software and a program called Opera from Opera Software ASA. But he added it remains unclear just how big an impact Google can have. “We have long years of testing and years of learning about how to make browsers,” Mr. Lilly said. “Chrome is new.”