BP has bought terms such as 'oil spill' from search engine providers including Google to help direct Internet users to its website as it attempts to control the worst oil spill in US history.

A spokesman said BP would pay fees so its own website would rank higher or even top in the list of advertisements that appear alongside search results when Internet users search on terms such as 'oil spill,' 'volunteer' and 'claims.'

BP did not say how much it was paying for the service but US President Barack Obama has criticised the company for spending $50 million on TV advertising to bolster its image during the crisis.

BP said it wanted to help people who were trying to access information on the BP website to find it more readily, rather than intending to draw away hits from other sites.

'We know people are looking for those terms on our website and we're just trying to make it easier for them to get directly to those terms,' the spokesman told Reuters.

Google allows companies to bid for the search ads that appear alongside, and sometimes above, its standard search results. The specially designated 'sponsored links' are distinct from Google's actual search results, such as news articles and blogs, for which Google does not permit companies to pay to influence their rank.

A recent search on Google for the phrase 'gulf spill' brought up an ad for BP at the top of the page, with the text 'Info about the Gulf of Mexico Spill Learn More about How BP is Helping,' as well as eight search ads from various organizations including the Environmental Defense Fund and the Volunteer USA Foundation.

The largely green and white BP.com website has a large red button at its centre highlighting the 'Gulf of Mexico Response.' The right hand side of the response site has a list of buttons advertising information on claims.

BP is trying to control oil spewing from a ruptured well on the seabed in the Gulf of Mexico by using a containment cap. – Reuters