INDIANAPOLIS (AP) - Formula One's U.S. Grand Prix won't return to the Indianapolis Motor Speedway next year after officials failed to reach a new deal.

Speedway CEO Tony George said Thursday he and F1 boss Bernie Ecclestone agreed not to schedule the event for 2008. The only American-based race on the F1 schedule had been held at Indianapolis the past eight years, drawing some of the biggest crowds on the circuit.

''We did agree it was prudent to try and leave the door open for the future,'' George said. ''My sincere hope is that we will have an opportunity to bring it back in the not-too-distant future.''

George, who had set Thursday as the deadline for reaching an agreement to extend the contract with F1, said he did not believe a U.S. Grand Prix would be held elsewhere next year, but that such a decision would be up to Ecclestone.

George had said last month he was confident he could reach a new deal with Ecclestone after the two met during U.S. Grand Prix weekend in Indianapolis.

But Ecclestone repeatedly said F1 did not need to race in the United States, although he mentioned the possibility of moving the U.S. Grand Prix to New York or Las Vegas.

George said Thursday it was a ''great disappointment'' that F1 would not be returning to the 2.6-mile, 13-turn road course that was built inside the speedway's famous oval to attract the series.

''It's not fair to us, it's not fair to our customers, the loyal core of Formula One fans, to just go on indefinitely on hold,'' he said.

Attendance figures are not released at Indianapolis, but estimates have been around 125,000 each of the past six years. The inaugural race in 2000 drew more than 200,000.

The event was marred in 2005 when 14 of the 20 drivers pulled off the track just before the start over concerns about the safety of the Michelin tires used by seven teams. Afterward, George refused to wave the checkered flag or join Michael Schumacher in the winner's circle.

Last year's negotiations to extend the deal dragged into August before the two sides agreed to a one-year deal. Speedway officials had said they wanted a more permanent solution this time.

Despite F1's absence, the speedway could still be the site of three races next year as track officials expect to announce a deal with MotoGP, the international motorcycle racing series, next week.

Besides the Indianapolis 500, the speedway also is the site of NASCAR's Allstate 400 at the Brickyard on July 29.

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