This is a steep decline from the 13% share held by Netscape at the same time last year, said Geoff Johnston, vice-president of product marketing for StatMarket, WebSideStory's Web site design and software developer service.
Microsoft's Internet Explorer (IE) holds an estimated 96% of the market, up from 87% a year ago.
The Netscape browser, owned by AOL Time Warner, had held steady with an estimated 13% marketshare over the 14-month period leading to the release of IE 6 about a year ago.
Effective and aggressive marketing on the part of Microsoft, IE's availability with Windows and the failure of new versions of Netscape to win over users helped IE grab an even larger share of former Netscape users, Johnston said.
IE 6 started stealing marketshare from Netscape soon after it was launched and within six months had pushed Netscape's share down to 7% in late March.
WebSideStory's figures were compiled independently based on a random daily sample of 20 million visitors to thousands of Web sites that use its HitBox visitor analysis service.
Figures showed 3.4% of the visitors were using a Netscape browser, 96% using IE and less than 1% were using the Opera browser from Opera Software ASA.
Despite the bleak figures for Netscape, it still holds a usage share of more than 7% among Web users in Switzerland, and in Germany, Canada and the US its market share is more than the 3.4% global market share estimate.
"There are pockets of resistance in certain countries, but unless AOL makes a move soon, Netscape may find itself battling Opera for the last 1% to 2% of the market," Johnston said.
Netscape announced a preview release of its Netscape 7.0 Web browser in May. AOL Time Warner also has said it was considering dropping IE from its America Online Internet service in favour of technology developed by its Netscape Communications subsidiary and open source software contributors.