The launch of a new global touring festival, Sonisphere, headlined by Metallica, has provoked a war of words between promoter Stuart Galbraith and his former employer Live Nation U.K., which operates the rival Download festival.

Sonisphere was unveiled today by Galbraith, series producer and director and CEO of Kilimanjaro Live, and John Jackson, festival creator and director and Metallica's booking agent at K2 since 1985. AEG, which backs Kilimanjaro, is also supporting the new festival.

The 60,000-capacity camping festival Sonisphere will be staged over two nights at Knebworth, Stevenage in the U.K. Linkin Park will headline on Aug. 1 and Metallica will top the bill on Aug. 2. Metallica will also headline Sonisphere festivals at Nijmegan, Holland with support from Slipknot (June 20), Hockenheim, Germany with Die Toten Hosen (July 4), Barcelona with Slipknot (July 11), Hultsfred, Sweden (July 18) and Pori in Finland (July 25) with Linkin Park. More artists are to be confirmed.

"I always had this idea of creating a truly global festival touring brand, rather than booking my acts piecemeal into pre-existing events," Jackson tells Billboard.biz. "It seemed kind of haphazard and also very difficult some of the time because of the geographical locations."

The Sonisphere concept was hatched by the pair at the London O2 arena Led Zeppelin reunion in Dec. 2007. "This isn't an Ozzfest - you're not going to see Metallica coming back year after year," says Galbraith. "The event will have its own identity, its own brand. But we are very excited and happy that we've got Metallica to launch the first six. They are bigger than ever in Europe."

Jackson adds that Metallica will likely be involved in further launches for Sonisphere in 2010; he is considering dates in Eastern Europe, Russia, Italy and Germany.

Galbraith was previously promoter of the Monsters Of Rock U.K. shows at Donington Park, Derby and, during his spell as managing director of Live Nation U.K., he was responsible for the Download rock festival at the same location.

Sonisphere will feature two stages with up to seven bands each, in contrast to the approximately 100 acts that Download hosted over three days last year.

"They will run alternately with five minute gaps and you'll see everything we put on the poster," says Galbraith. "It's about quality rather than quantity. Certainly in my latter-day period at Live Nation, I was dealing with increasing numbers of complaints from fans that the [Download] band quality was diminishing and that the scheduling of the festival meant that they couldn't get to see half of what they wanted to see."

Asked about the rivalry with Download, he tells Billboard.biz: "I think the market [will decide] and the fans will vote with their feet. I have to say, I think Download last year had a few things that were not done as well as they should have been -- both the layout and the booking policy I thought were bad.

"I think if I had have been at Live Nation still, I would have taken last year off. I would have preferred to have been really honest and said to the fans -- as we did with Monsters of Rock on two or three occasions -- there is not enough good talent out there this year, we can't deliver you the quality of festival that we want to, and we're going to give it a break and we promise we'll do everything we can to come back next year and be bigger and better and stronger than ever."

Galbraith last worked on Download in 2007. Last year's headliners included Kiss, the Offspring and Lostprophets; the arena site was moved to another part of Donington because of work on a new Formula 1 venue for the British Grand Prix.

Live Nation U.K. COO and festival director John Probyn is preparing to unveil Download's line-up tonight (Feb. 9) - it takes place on June 12-14 - and he defended the event.

"There's only one group of people we pay attention to and that's the fans," says Probyn. "They tell us [online at the forum] they love the number of bands, they feel that they get value for money, it's not just about the big headliners it's about finding new bands. Download is here to stay."

He adds: "Metallica have played Download four times I think [including a 2004 Scotland Download leg]. If you look on the forum, people are saying 'Metallica, so what? Seen it before.' They toured the year before last, they were out last year, they're out again this year."

Asked about his new rival, he adds: "I don't really care. Last year we were up against Reading and Leeds [festivals] who had a very similar line-up to what we'd normally have, and we still did our numbers and we're happy. This year if we've got something else to compete with, then fine."

Probyn admits there were problems with the site last year - "we didn't get it right" - but says the event has secured a better location with improved facilities for 2009.