Officials with the U.S.-based X Prize Foundation will unveil plans for the largest international cash contest to date next week, but they are keeping details on the new challenge under wraps.

The specifics on the new cash prize, which is promised to be in the "tens of millions of dollars" and bankrolled by "a very exciting and well-known Fortune 500 company," will be revealed Sept. 13 at the WIRED NextFest technology fair in Los Angeles, Calif., the foundation announced Monday.

"The actual announcement and details on what the prize is and its sponsorship will be released on that day," X Prize Foundation spokesperson Sarah Evans told SPACE.com. "We're very excited and we'll share it with the world on Sept. 13."

Foundation officials said the new purse and contest will be "the largest international prize in history," and promised more details after the NextFest opening ceremony next week.

Led by Peter Diamandis, the Santa Monica, California-based X Prize Foundation has offered a series of cash-prize competitions to support the development of new technologies. Since awarding its first cash award?the $10 million Ansari X Prize for privately built spacecraft?the foundation has since broadened its mandate to include prizes for feats in the genomics and the automotive fields.

"We currently have new X Prizes in development in the areas of space, energy, medicine, education and the social arena," the foundation has stated on its Web site.

Won in 2004, the Ansari X Prize marked the foundation's first contest to offer a cash award for privately funded technological prowess. The competition called for teams to launch their homegrown, piloted spacecraft into suborbital space, an altitude of at least 62 miles (100 kilometers), twice in two weeks. Mojave Aerospace Ventures, a team led by aerospace veteran Burt Rutan and financed by Microsoft co-founder Paul Allen, took home the contest's $10 million purse after two successful flights of the air-launched SpaceShipOne vehicle.

This October, the X Prize officials will also hold the annual, spaceflight-themed Wirefly X Prize Cup in New Mexico. There, the foundation expects to oversee the second Northrop Grumman Lunar Lander Challenge for NASA, as well as award the first-ever $9,000 Pete Conrad Spirit of Innovation purse to high school students.?

The foundation is also offering the $10 million Archon Genomics X Prize for any team capable of sequencing 100 human genomes in 10 days. It is also drawing up plans for a multimillion-dollar reward for the first group to successfully design, build and sell a 100 mile-per-gallon automobile.

  • SPACE.com Video Player: Impressions & Dreams: Peter Diamandis
  • Future of Flight: Space Tourism, Investment and Technology
  • Complete Coverage of the Wirefly X Prize Cup