Leading search engine-based company Google continues to benefit from the lion’s share of web-based advertising spend and search activity, according to a new report from advertising agency, ZenithOptimedia.

ZenithOptimedia’s figures show that Google increased its combined share of both display and pay per click (PPC) advertising from 34.9% in 2006 to 44.1% in 2010.

This compares with an increase in Facebook’s share of the ad revenue market over the same period, from only 0.2% to 3.1%

Over the same period, rivals Microsoft and Yahoo! suffered more than a 50% drop in their market share; whilst AOL’s share of the market declined by 75%.

Zenithoptimedia’s research also shows Google continuing to be the dominant player in the search engine field, with 85% of all searches worldwide currently being made through its search engine facilities.

By contrast, the combined share of global searches using Yahoo!, AOL and Microsoft stands at just 13.8%.

Google’s continued strength in the market is believed by many commentators to have been helped significantly by its purchase of both YouTube and DoubleClick.

On a generally positive note, ZenithOptimedia says that despite recessionary fears, it expects general online advertising revenue to continue to grow over the next couple of years; with its estimate for the UK showing an increase from a current £1.17 billion to £1.29 billion in 2014.

ZenithOptimedia says that this growth will be partly assisted by major events in 2012, including the Olympics and the European Football Championships.