Team bosses said that they had agreed in principle on a system to replace the extended single-lap qualifying in a meeting at the European Grand Prix.
"It's two 20-minute sessions separated by a 20-minute break," said Jaguar's Tony Purnell on Saturday.
He said each driver would be allowed six laps in each Saturday afternoon session with cars running on low fuel for flat-out performance.
The starting grid would be decided by an aggregate of the best runs in each half.
Parc ferme, with cars under strict International Automobile Federation (FIA) supervision, would be imposed immediately after qualifying.
"It's not detailed and it's very much subject to the rules actually being produced and everybody agreeing," cautioned Purnell. "It would be a big mistake to say this is what is going to happen. That would be premature."
"There was talk about Silverstone and there was some talk about Indianapolis," he said of the target date for Introduction.
Others said Indianapolis on June 20 was too early and the British race on July 11 was most likely.
BAR boss David Richards said some teams had wanted the second 20-minute session to be run on race fuel levels but Ferrari's Jean Todt had argued that could be dangerous, with some cars crawling round to conserve fuel after completing their laps and others still going full tilt.
Formula One has had several qualifying systems, with the old one-hour free-for-all abandoned at the beginning of last year for a new format with one hour sessions on Friday and Saturday and drivers having one timed lap on their own in each.
That was refined for this year, with the two parts shoe-horned into one extended back-to-back session on Saturday.
Under current rules, drivers are not allowed to refuel their cars between qualifying and the race.
That has led to cars starting on different fuel loads and spectators kept in the dark about the real performance levels in qualifying with the fastest driver not always on pole.
After broadcasters and many inside the sport complained that the system was too boring and too long, longer even than the race in some instances, it was tweaked again with an interval between the two sessions.
