Microsoft released a web browser on Wednesday that includes a feature that could affect the advertising model of internet rivals such as Google.

The Internet Explorer 8 browser’s InPrivate setting lets users access websites without disclosing their browsing habits, which websites need to be able to do to deliver targeted advertising. This is a business Google has just moved into through its acquisition of DoubleClick.

John Curran, a director at Microsoft UK, said “some people will always want to be ‘InPrivate’, but there is a trade-off” – meaning that although people’s privacy will be protected they will not automatically receive data relevant to their interests.

Google has faced a public outcry over the amount of information it collects from users of its services. David Mitchell, an information technology analyst at Ovum, said: “If the hype around privacy gains more credibility, more people will hit the private button. There is a potential threat here to click-through [display] advertising.”

Google was unavailable for comment. However, one person familiar with its business said that if Microsoft’s browser succeeded in changing user behaviour it could pose some risks to Google’s attempts to expand its display advertising business. Google gets 90 per cent of its revenue from search advertising, which would not be affected, but it hopes display ads will become an important source of revenue.

The browser became available as a “beta” version last night and will eventually be included with the Windows operating system.