Online ad spending in the US rose by 26% last year, reaching a total of $21.2bn (£11bn) in 2007, with the share of ad revenue from search advertising continuing to rise.

According to the IAB’s full year report, 2007 was another record year for online ad spending, the fourth in a row.

Online ad revenues overtook that of cable TV and radio advertising for the first time last year, and now rank third behind TV and newspaper ads.

Spending on search advertising rose by 30% over 2006, reaching a total of $ (£4.5bn) for 2007. Search ad revenues accounted for 41% of all online advertising spending.

Display advertising accounted for 34% of total online ad spend, followed by classified advertising on 16%.

Meanwhile, Google’s share of the US search market continues to rise, according to the latest search stats from Hitwise.

Google was responsible for 67.9% of all searches in the US in April, up nearly 1% on the previous month. This is a new record high, according to the web measurement company.

The search market share of Yahoo and Microsoft fell to all time lows for both search engines. Yahoo accounted for 20.3% of US searches last month, while Microsoft’s Live Search had just 6.3% of searches, with on 4.2%.