Microsoft is the dominant firm in the British internet advertising industry.

According to figures from Nielsen/NetRatings, over the first four months of this year the company saw its proportion of online display campaigns increase by 32.6 per cent compared to the same period in 2006.

Internet analyst Alex Burmaster said: "While it's not surprising to see technology and communications brands embracing online advertising, many will note how the finance sector has an equally keen appetite for advertising on the web."

However, Mr Burmaster added that "unlike other areas of online [operations], advertising isn't dominated by the few".

He pointed out that the top 20 online advertisers account for seven per cent of all internet marketing campaigns.

The study also revealed that the five major search engines accounted for some 96 per cent of all searches carried out by British users.

Earlier this week, research from Hitwise indicated that an increasing amount of clicks to e-commerce websites are derived from search engine queries.