"Many other companies have already stopped supporting older browsers like Internet Explorer 6.0 as well as browsers that are not supported by their own manufacturers. We're also going to begin phasing out our support, starting with Google Docs and Google Sites," Rajen Sheth, Google Apps senior product manager, wrote in a Friday.

The announcement comes more than two weeks after Google reported that its servers had been the target of attacks originating in China. Those attacks targeted a vulnerability in IE 6, for which Microsoft has since issued a fix.

Support for IE6 in Google Docs and Google Sites will end March 1, Sheth said in the post. At that point, IE6 users who try to access Docs or Sites may find that "key functionality" won't work properly, he said.

Sheth suggested that customers upgrade to Internet Explorer 7, Mozilla Firefox 3.0, Google Chrome 4.0 or Safari 3.0, or more recent versions of those browsers.

According to , IE6 has 18 percent market share among browsers.