Innocent, the fruit smoothie company, is ranked as the third-fastest growing unquoted company in the UK and is the sector brand leader.

In 1998, when many young entrepreneurs were fixated on how to make money out of the internet, three university friends keen to set up a business spotted a different opportunity: fresh, healthy drinks.

Seven years later, many of the dotcom ventures established by aspiring internet-millionaires have failed. But Innocent, the smoothie company created by Richard Reed, Jon Wright and Adam Balon has blossomed.

Ranked as the third-fastest growing unquoted company in the UK last year by research group Fast Track 100, Innocent has been profitable for six out of its seven years, with annual sales almost tripling over the past year to £26.8 million (€39.4 million), according to market researcher AC Nielsen.

Innocent is now the brand leader in the UK smoothie market, which research groups estimate to be worth £60 million to £70 million annually.

Pete & Johnny's - the first UK smoothie company - has annual sales of £13 million while private label brands make up around one-third of the market.

Innocent still has the feel of a start-up. Its headquarters in Shepherd's Bush, west London, has red beanbags, purple couches and floors covered with fake grass. Its young employees, some of whom work seated under large canvas umbrellas, have stuck their baby photos on the walls.

But Mr Reed (32) makes it clear that Innocent is a serious company with global ambitions. "We want to be in every market where there's a demand for natural, healthy food."

Innocent's timing has been astute.

As concern grows over rising levels of obesity in Europe, consumers are paying more attention to what they eat and drink and multinational food and beverage companies are trying to tap into changing consumer tastes by selling healthier products.

The size and global scale of some of Innocent's competitors does not faze Mr Reed. He says Innocent has other advantages. "We innovate more, we are faster to market, we can deliver better quality ingredients at a better price-point than the big guys because of the way our business is structured."

The company prides itself on producing natural drinks, including 13 kinds of smoothies, most of which contain only fruit. It does not use preservatives, concentrates, sweeteners or additives.

Its business is sufficiently robust to have attracted takeover proposals from its multinational competitors, incl-uding Pepsi (which this year bought Pete & Johnny's instead).

Mr Reed, who will not disclose Innocent's profit margin - saying only "it's healthy but it ain't obscene" - estimates Innocent has received about 30 approaches. "There isn't anyone you can think of that hasn't initiated discussions."

The interest is a far cry from the company's early days, when it struggled to find willing investors.

Innocent's founders were turned down by high-street banks, the small business loan guarantee scheme and the venture capital community.

Told the only way they would get anywhere would be to find someone rich, they e-mailed as many people as they could think of.

"We sent out an e-mail to every single person that we knew, everyone that we'd ever worked with or met. We put in the subject line: 'Does anyone know anyone rich?'"

They found an American, Maurice Pinto, who lived in the UK and who had invested in a wide range of businesses, including organic retailing. He put up £250,000 and became the fourth shareholder in the group, retaining a 20 per cent stake.

In spite of approaches by potential suitors, Innocent is determined to remain independent. "That's not the path we're on," Mr Reed says. Nor is a public listing in the immediate future, although it is possible. "I'd never say never to anything," he says. The company creates its own recipes, testing them at its glass-enclosed development kitchen in Shepherd's Bush, and finds its own fruit, but outsources production to four UK manufacturers. It claims to be Europe's biggest buyer of soft fruit.

The smoothies, which appeal to consumers whom Mr Reed describes as "slightly more female, slightly more affluent, slightly younger," are priced at the high end of the fruit juice market, selling for £1.70 to £1.80 in "on the go" plastic bottles, and for £2.99 in larger take-home cartons.

Innocent has also recently launched a children's range, retailing at 70p.

Mr Reed left a career in advertising to start up Innocent and knows how to market his drinks, arguing that their health benefits justify their higher price.

"The orange juice going into the kids' product is Costa Rican, organic Rainforest Alliance-accredited orange juice. There is not an orange grown that is better tasting, better quality, better for you and more ethically sound than the orange that is going in here."

He is also ambitious. "We want to be the most talent-rich company in Europe."

Innocent employs a range of people - "we've got hippies, we've got management consultants, we've got PhDs, we've got people who graduated highest in their class at Harvard" - at its offices in London, Manchester, Dublin and Amsterdam, and is on the verge of opening an office in Paris.

Innocent's main market is still the UK and Ireland, which accounts for 90 per cent of its sales, but its smoothies are also sold in the Netherlands, Belgium, Luxembourg and France. It eventually plans to expand within and beyond Europe.

"We have the trademark registered in every country that we think it can become business relevant."

These include the US, Australia, New Zealand, China, India and countries in South America.

For the time being, Innocent is focused on drinks. But it could extend its brand into other products, such as baby foods, and Mr Reed has even thought about a spa.

"A wood cabin where you can lie back and watch the sun set, and eat loads of fresh organic fruit and veg."