On 2 March, Google accidentally posted internal information to its investor relations website, the company confirmed in a US SEC (Securities and Exchange Commission) filing yesterday.

"Our ads business for the moment is healthy and growing and we're on a strong trajectory... projected to grow from $6bn [about £3.4bn] this year to $9.5bn [£5.5bn] next year based purely on trends in traffic and monetisation growth," the post said, in one of the statements not intended for publication.

However, the filing said the company couched that optimistic forecast with a word of caution by adding: "Strong competitors are attempting to aggregate traffic... AdSense margins will be squeezed in 2006 and beyond."

"These notes were not created for financial planning purposes, and should not be regarded as financial guidance," Google said in the filing. The company does not normally provide financial guidance regarding earnings and profits.

The SEC filing confirmed the accuracy of estimates made in the forecast regarding employee stock options. "The statement regarding the stock-based compensation charge of $342m [£196m], which relates to stock awards granted to employees and directors prior to 2006, is a materially accurate reflection of Google's current expectations," it said.

The gaffe was the second in recent weeks for Google. On 28 February, Google chief financial officer George Reyes told a Merrill Lynch conference that its advertising revenue growth would inevitably slow.

"Our revenue growth rate has generally declined over time and we expect that it will continue to do so as a result of the difficulty of maintaining growth rates on a percentage basis as our revenues increase to higher levels," Google said in a statement released 28 February.