The company, which stubbornly refuses to give advice to analysts tracking it, posted a presentation to its web site that inadvertently included some slides apparently dating from the fourth quarter 2005, containing internal growth projections.

The search firm said revenue from its advertising business, which makes Google almost all of its money, was healthy and growing, and was projected to grow from $6bn this year [2005] to $9.5bn next year.

The presentation noted that AdSense margins will be squeezed in 2006 and beyond. AdSense is Google’s contextual advertising system. A large portion of revenue from Adsense is given to partner web sites that display its ads.

The presentation was pulled, and Google was obliged to inform investors of the gaffe. The company said in a Securities and Exchange Commission filing that the slides were from an early fourth quarter 2005 product strategy meeting and were not guidance.

These notes were not created for financial planning purposes, and should not be regarded as financial guidance, Google said in the filing, conspicuously not denying the accuracy of the numbers.

Google’s actual reported 2005 revenue was $6.139bn. So if the slides were an accurate reflection of Google’s hopes at the start of the fourth quarter, it did in fact do a little better than it was expecting.

But the company did deny that the color given on shrinking margins is currently accurate, saying, the statement with respect to AdSense margins does not reflect Google’s current expectations.

The slides also apparently included details on estimates of the cost of stock-based compensation. It said the cost this year of stock awards granted prior to 2006 would be $342m, which Google said was a materially accurate reflection of the truth.

The slide deck also included some text relating to GDrive, an unannounced service whereby Google will let people store all their data at Google’s data center, rather than on a computer they control, which is a more usual state of affairs.