Next year's FIA World Endurance Championship will kick off at Silverstone with a double header weekend incorporating the first round of the relaunched European Le Mans Series.
The Silverstone 6 Hours has been moved from August to April as part of a calendar reshuffle caused by the removal of the Sebring 12 Hours from the schedule and a desire to reduce costs.
The ELMS will race on the same bill in a bid to raise the profile of a series that this year was hit by a rash of race cancellations.
WEC boss Gerard Neveu, whose group is taking over the running of the ELMS for 2013, said: "We want to relaunch the ELMS and use the exposure of the WEC to help achieve that."
The ELMS race, which will be of a duration that has yet to be determined, will take place on Saturday, April 13 and the six-hour WEC event 24 hours later on the Sunday. The ELMS field will use the old pits, while the WEC grid will be based in the new Silverstone Wing complex.
Silverstone will be one of two double-headers run under the Super Endurance Weekend banner. The US event at the Circuit of The Americas in Austin, Texas in September will be a joint event with the American Le Mans Series, which will have its race on the Saturday.
Sebring's disappearance from the calendar had been widely predicted. Neveu explained there were a number of reasons for removal this year's opening venue.
"Imagine if we had 32 or 34 WEC cars and 35 in the ALMS," he said. "It would be difficult to tell people that there was not room for everyone."
He added that it was important that the WEC has its own identity and that a desire to reduce costs had resulted in all non-European races happening in second half of the season after the Le Mans 24 Hours.
The WEC will remain at eight races. Neveu explained that there had been approaches from tracks and promoters for further races both in Europe and elsewhere, but the desire to control costs meant these were not pursued.
2013 FIA World Endurance Championship April 14 Silverstone 6 Hours (GB) May 4 Spa 6 Hours (B) June 22/23 Le Mans 24 Hours (F) August 31 Sao Paulo 6 Hours (BR) September 22 Austin 6 Hours (USA)* October 20 Fuji 6 Hours (J) November 10 Shanghai 6 Hours (PRC)* November 30 Bahrain 6 Hours (BAH) * remains provisional