Google's official blog was hacked at the weekend and a fake message left saying the company had decided to cancel a joint project with eBay.

The intrusion is the second time this year that the blog has fallen into others' hands - in March, Google staffers deleted the Google Blog by mistake and someone briefly took control of the Web address.

In the most recent incident, someone used a bug in Blogger, the service the Google Blog uses, to break in. The resulting post was riddled with grammatical and spelling errors that said Google had ended its click-to-call advertising project with eBay because it was "monopolistic".

The next day, Karen Wickre, from the Google Blog team, alerted readers about the false posting and said the Blogger bug had been fixed, without detailing the breach. The eBay project remains alive and well, she wrote.

The Google Blog, at http://googleblog.blogspot.com/, is one of the company's main communication tools. As official corporate messages similar to press releases, its postings often trigger news reports, analyst recommendations and investor decisions.