By Victoria Lindrea BBC News entertainment reporter

The show has an exclusive nine-month run in Toronto

Based on JRR Tolkien's fantasy trilogy, it has taken four years to bring it to the stage and promises to be a theatrical extravaganza of unparalleled ambition.

A three-hour epic, peopled with hobbits, elves and Black Riders, it will feature a 65-strong cast of actors, musicians and dancers, and at C$27m (�13m) is reported to be the most expensive musical ever staged.

In keeping with the effect of Peter Jackson's films, which saw New Zealand re-marketed to scores of Rings fans as Middle Earth, Toronto - Canada's largest city - hopes to draw Tolkien's substantial following to their shores.

The local government recently announced that they would be contributing C$3m (�1.4m) towards staging the musical in the city.

The musical will cash in on the popularity of Peter Jackson's films

Bill Allen, the deputy minister for tourism for the province of Ontario, believes the cost of not investing could be higher.

"We realised in the last couple of years that if you don't have new and exciting things to do, people go somewhere else," he told The New York Times.

"They want an experience they can't find anywhere else."

His thoughts are echoed by Bruce MacMillan, president of Tourism Toronto, a private tourism body investing C$3m to market the musical internationally.

"Next year, Middle Earth becomes the newest Toronto neighbourhood."

Slim risk

While it is a major investment for a provincial government - and marks a rare foray by the state into commercial theatre - recent news suggests it poses only a slim risk.

The substantial Monty Python fan base has seen the Broadway production of Spamalot return its investment in less than seven months.

With the vast Tolkien fan base - the novels have sold in excess of 200 million copies - the show should do good business in advance sales alone.

Early marketing campaigns are already underway in nearby American cities including Detroit and Cleveland, and ticket sales are approaching C$10m (�4.8m).

Given Toronto's exclusive deal to stage the show for an initial nine-month run, a critically acclaimed production - with tickets averaging C$115 (�55) in a 2,000 seat theatre - could deliver serious revenue.

Only in the theatre are we actually plunged into the events as they happen Matthew Warchus, director

For investors, including Toronto theatre owner David Mirvish who owns the Princess of Wales theatre where the show will appear, staging the Rings was a creative and commercial opportunity not to be missed.

The event musical marks a chance for Toronto to win back its status as a prestigious home of musical theatre, a reputation that has dwindled in recent years.

Mirvish, whose family owns three Toronto theatres, was approached after it was found no London theatre with sufficient capacity was available to house the production.

The musical is now not expected in the West End before autumn 2006 - and on Broadway until 2007.

"Toronto really wanted this premiere. The Tolkien books and films are hugely popular in Canada," said producer Kevin Wallace, shortly after signing the deal in Canada.

Unique depiction

But fans expecting a reversioning of Peter Jackson's film trilogy may be disappointed. The show will feature no Hollywood stars, limited 'special effects' and the epic battle scenes will, by necessity, be considerably diminished.

The production, while firmly grounded in Tolkien's masterpiece, will ally physical theatre with a range of musical traditions including Finnish and Indian influences, to deliver a unique retelling of Tolkien's fantasy.

According to Wallace, there will be "non-stop music", with action sequences "like mini-symphonies", plus circus-style acrobatics and speeches delivered in a range of "tongues" - including Elvish.