GENEVA -- Hybrids aren't just for fuel economy any more.

Ferrari and McLaren both on Tuesday unveiled sleek hybrid supercars sculpted from carbon fiber at the Geneva Motor Show.

''LaFerrari" is the name of the new special edition Ferrari.

''Owners say they have a Ferrari," Chairman Luca di Montezemolo said. ''This is THE Ferrari."

Montezemolo said the electric engine has a performance appeal that is proving a draw to Ferrari owners.

Only 499 of the models will be built -- and some 700 people, many of them Ferrari owners already, have registered interest, requiring a selection process for the future owners. The price tag: $639,000.

The McLaren P1 in a glittery racing yellow set off by hash-marked slate gray cuts a racetrack figure.

The hybrid technology has performance advantages because the electric engine fills in the gap before the turbo engine kicks in, P1 program director Paul McKenzie said. It's a tiny effect, but everything counts in supercars.

The P1 can do 0-180 mph in under 17 seconds. It sells for $1.3 million, with just 375 in the series.