RESTON, Virginia: Google continues to increase its lead over main rivals Yahoo and Microsoft in the race for search advertising dollars, according to the latest US data released by global internet information provider comScore.

After a shaky start in the year's first quarter, when Google experienced a plunge in paid-click revenue growth to just 1.8%, the search Goliath's ad income increased sharply during April, achieving a better than expected year-on-year growth of 20%.

Paid clicks for Microsoft and Yahoo, however, declined during the month, respectively by 9% and 4.4%.

Google's seemingly weak start to 2008 triggered a tsunami of speculation as to whether Sergey and Larry's seemingly invincible machine was about to run out of gas – precipitating a sharp fall in its share price.

Google, however, kept its cool, dismissing the decline as a temporary situation due to new quality initiatives: reducing the dimensions of ads to avoid accidental click-throughs; as well as the number of paid search results returned by a given query.

Data sourced from Wall Street Journal Online; additional content by WARC staff