Google is an instantly recognised brand

According to the research from net measurement firm Nielsen/NetRatings, Google is the search engine of choice for more than 55 million Europeans.

The phrase 'to google' has entered popular parlance as a verb to describe an internet search.

But analysts say it faces growing competition from MSN and Yahoo, which are investing in search technology to try to win back web surfers.

Rivalry

As well as being the most popular search engine, Google also enjoys the most number of pages viewed and the most amount of time spent on the site.

Most search engines have only fleeting visits from surfers but Google is attracting users for more than 10 minutes per month.

TOP FIVE IN EUROPE Google: Audience of 55 million MSN search: 27 million Yahoo search: 12 million Google image search: 10 million AOL search: 5 million Source: Neilsen/NetRatings

Despite its continued popularity, rivals Yahoo and MSN are determined to challenge its crown.

"Google's dominance may appear unshakeable, but with some of the biggest brands on the internet developing rival search technologies, the next 18 months will prove crucial for this sector," said Tom Ewing, European market analyst for Nielsen/NetRatings.

The battle may not be just about technology though.

"Google's branding is so strong, it has entered the language and become a fundamental part of people's searching habits," he told BBC News Online.

"It may be possible to build a technically better search engine but it will be difficult to make people love it."

Google's web index is huge, carrying more than six billion items.

But it has also become a victim of its success with some companies manipulating the technology to get their products to the top of the list, creating a new breed of search engine spam

For the time being though, Google is riding high. At the beginning of the year, its founders Sergey Brin and Larry Page joined the Forbes magazine list of world billionaires.