Indianapolis thus joins California's Laguna Seca circuit on next year's calendar although - unlike Laguna - the Indy event will feature all three grand prix classes, with the support 125 and 250cc World Championships also making the trip across the Atlantic.

With Laguna Seca already holding the 'US Grand Prix' title, the new event will be called the 'Red Bull Indianapolis GP' and first take place on September 14, 2008. Red Bull is also the title sponsor of the Laguna Seca race.

In order to host MotoGP, the previous F1 road course will be substantially modified. As rumoured, the race direction will be reversed, meaning that the new layout will run in the same direction as the facility's oval events. The new turn one will be tighter than the old final F1 corner, which used part of the oval's banking, while a new section of corners has also been added early in the lap. The new course will feature 16-turns and be 2.601-miles in length.

"We are very happy to be able to add this event to the MotoGP calendar because tradition and history play such a big part in our sport, and nowhere in the world has as much motorsport history as Indianapolis," said Dorna CEO Carmelo Ezpeleta.

"The U.S. is obviously a very important market to us, and when we returned to Laguna Seca a couple of years ago for the Red Bull U.S. Grand Prix, it was an instant success. The next step was to come to Indianapolis, and now to be able to say we have two MotoGP events in the United States shows just how far our sport has come in recent years. We hope that the Red Bull Indianapolis GP will be another success story, and we are already looking forward to next year's first event with anticipation."

"We welcome the excitement and passion of MotoGP racing and its fans to the Indianapolis Motor Speedway for the inaugural Red Bull Indianapolis GP," added Joie Chitwood, IMS president and chief operating officer. "The very first motorised race at IMS was on two wheels, so it's only fitting that motorcycles are returning as we approach the 100th anniversary of the track.

"Fans of MotoGP know just how thrilling this form of racing is, and our new road-course configuration will create even more side-by-side action and passing opportunities for the skilled riders."

As Chitwood indicated, motorcycles were the first vehicles to race at Indianapolis, in 1909, two years before the first Indianapolis 500 car race.

Five Americans have scored points in MotoGP this year, including reigning world champion Nicky Hayden - who has won his home grand prix for the past two seasons.

"I'm really excited about this race," said the Repsol Honda rider. "It is great that Red Bull is committed to the growth of MotoGP in America, and coming to such an historic track like Indianapolis Motor Speedway will be really special to me. It's like my home race. I'm sure all of Owensboro will make the drive up north!"

Less than a week ago, Indianapolis announced that it would not host a Formula One grand prix next season - however the MotoGP deal is said to be unrelated to F1's exit.

With the current 18 round MotoGP calendar unlikely to expand, the new Indianapolis event - for which a 'multi-year' agreement has been reached - is expected to be at the expense of the Turkish Grand Prix at Istanbul Park.

The 2007 US Grand Prix, round eleven of the world championship, starts on Friday.