Google has hired one of the top programmers who worked on the Firefox project, fueling new speculation that the search giant may enter the browser business.

The Mountain View, Calif.-based search company hired Ben Goodger, the lead engineer for the Mozilla Foundation's Firefox stand-alone browser, the number one competitor for Microsoft's Internet Explorer. As of Jan. 10, Goodger wrote in his blog Monday, he's been an employee of Google. Half of his time, said a Google spokesman, will be donated back to Mozilla so he can continue working on Firefox.

Google and Mozilla already have connections. The search firm sponsored a Mozilla developers' conference in August of last year, for instance, and Firefox 1.0's default home page is a slightly-customized Google search interface.

"My role with Firefox and the Mozilla project will remain largely unchanged," wrote Goodger. "I remain devoted full-time to the advancement of Firefox, the Mozilla platform, and browsing in general. While I will be spending more time at Google, I will work out of the Mozilla Foundation offices regularly as the need arises."

In the past, Google chief executive Eric Schmidt has said that the company is not building a browser. On Tuesday, the company neither confirmed nor denied that these plans have changed. "Many of Google's products aim to enhance the browsing experience," a Google spokesman said. "We do not comment on speculation about product development."

That, however, could leave room for Google to add to or customize Firefox. Like all browsers, Firefox can be tweaked by adding plug-ins, which Firefox calls "extensions."

Firefox is the second-most popular browser here in the U.S. and also around the world, according to Web analytical firms such as WebSideStory and OneStat. Since its November release, some 20 million copies of Firefox 1.0 have been downloaded, the Mozilla Foundation claims.