MOUNTAIN VIEW, California: Shock, horror, is gilt-edged Google losing its luster? Online researcher ComScore reports that the number of paid ad click-throughs totalled 532 million during January, marginally down on the search giant's 533m in the same month last year.

In the previous five months, paid clicks, which drive Google's revenues and profits, had increased by between 12% and 60%.

The latest flat results have alarmed investors, who saw shares in the world's number one online search business dip to an 11-month low earlier this week.

Until now analysts had chosen to believe Google could withstand the US credit crunch and its unwelcome knock-on effects for the nation's economy.

But, says Clayton F Moran, from the Stanford Group: "We don't see a compelling reason to buy the stock right now because we think there's going to be a rocky few months ahead for Google."  

The search titan's executives acknowledged the click slowdown, but played down the blip by claiming it had been caused by a redesign of the system.

The revamp means fewer users are clicking on ads by mistake. Consequently, marketers may be willing to pay more for each click - or so Google claims.

Analyst Jordan Rohan, from RBC Capital Markets, agrees the design change may enhance Google's revenue per search and offset any declines in surfers' clich-thoughs on ads.

Data sourced from Washington Post Online; additional information by WARC staff