Microsoft's Internet Explorer halted the steady market-share advance of the Mozilla Foundation's Firefox browser in July, a website monitoring company announced on Friday.

Last month, IE, by far the most widely used browser, regained lost ground and pushed back the upstart Firefox for the first time since version 1.0 of the open-source browser was released late last year, according to NetApplications.com, maker of applications for monitoring and measuring website usage.

Firefox's share shrunk from 8.71 percent in June to 8.07 percent last month, while IE expanded from 86.56 percent to 87.2 percent.

Between January and June of this year, Firefox had posted monthly market share gains of between 0.5 and 1 percent at the expense of IE.

The browser’s advances in the market have been extremely impressive, and it remains impossible to tell whether July's results are the beginning of a downward trend for the open-source market or a one-off anomaly.

NetApplications.com has said in the past that reaching a 10 percent market share would be a milestone for Firefox that could help it win acceptance in the corporate market.

Apple's Safari ranked third and grew its share slightly from 1.93 percent to 2.13 percent, while AOL's Netscape, which once ruled this market, slid slightly from 1.55 percent to 1.5 percent. Opera Software ASA's Opera came in fifth, with a 0.49 percent market share.