American authors and fiction writers of any nationality whose books are published in English will shortly be able to enter a new British literary competition.

Worth £60,000, the Man Booker International prize will be awarded every two years and run alongside, rather than replace, the annual competition which is restricted to newly published work from the Commonwealth and Ireland.

Since the Man Group took over sponsorship of the annual literary prize, there has been speculation that the financial investments company would find a way to make US writers eligible.

Man - which has offices in London, New York, Chicago, Paris, Singapore and Sydney - clearly relishes the publicity from an international contest. "We hope to provide a new platform for writers around the world," explained Harvey McGrath, chairman of the Man Group, yesterday as he revealed details of what will be the largest literary prize in the UK.

"We do less in Europe than we do in America but clearly it's sponsorship. We are very pleased by the way our profile has been raised [so far]." The new international prize might follow the example of the Eurovision Song Contest, he said, enabling the awards ceremony to take place in the country of the previous winner.

The new prize was not intended to be a "lifetime's achievement award", insisted John Carey, the literary critic and Merton professor of English at Oxford University, who will be the chairman of the first panel of judges.

"The judges will be looking for originality and individuality," he said. "I want to find someone whose take on the world is not like anyone else's." Charles Dickens or Graham Greene, he suggested, were examples of authors with such distinctive voices.

"If we have learned nothing else from the 21st century, we have learned that we need to understand other cultures better. One way to do that is to understand their literature. I hope we will find someone who combines the serious with the popular and who will appeal to a wide readership and having something important to say.

Unlike the Man Booker prize, where publishers submit candidates, entries for the international trophy will be chosen by three judges who will whittle their shortlist down to 15 contenders. The aim is to reward living writers of "consistent excellence".

Prof Carey denied that it was an attempt to compensate writers overlooked by the existing prize or counter publishers' enthusiasm for photogenic young authors. "These things never affect the judges," Prof Carey declared. "The only thing is literary quality. I hope I will have already read most of the [likely entrants]."

Gary McKeone, the Arts Council's literature director, said: "There's always room for another good literary prize. I think it's terrific."

The existing annual Man Booker Prize for Fiction is worth £50,000. The Whitbread Prize Book of the Year, worth £30,000, is only open to writers resident in Britain or the Republic of Ireland for at least six months of each of the previous three years.

The International Impac Dublin Literary Award, worth €100,000 (£66,000), is open to authors of any nationality as long as their work is published in English. The Orange Prize is open to all women writing in English regardless of their nationality.

The two other judges of the new Man Booker International prize have yet to be named. The first winner will be announced in mid-2005.