LE MANS, France (AP) _ A Joest Porsche won the Le Mans 24 Hours for the second consecutive year after factory-backed Porsches dropped out while comfortably in front Sunday.

Michele Alboreto, Stefan Johansson and Tom Kristensen combined for the victory with more than 360 laps completed. Their car had led in qualifying on the 8.456-mile circuit, and averaged 126.9 mph in the race.

This was Porsche's 15th title, although it was from a private team with a Porsche engine. Last year, a Joest TWR Porsche won the race with three different drivers completing 354 laps.

``I think we started a little history with this car,'' team manager Ralf Juettner said of the 48 hours of victory over two years. ``It takes a lot of work and a lot of help from a lot of people.

``It was a good car and a great team, and of course good drivers.''

It was the first Le Mans success for Alboreto, Johansson and Kristensen. Both Alboreto and Johansson raced on the Formula One circuit.

Mario Andretti, seeking the only major international title he has yet to win, faltered again with problems plaguing his car almost from the start.

The winners stayed behind the top Porsches for nearly 20 hours, but took the lead when the second factory Porsche caught fire with 2 hours, 15 minutes to go.

The first factory Porsche of Thierry Boutsen, Bob Wollek and Hans Stuck was in front for nearly 14 hours _ since the second hour of the race _ before Wollek went off the road and stopped.

The second factory car was holding a lap lead when it burst into flames after 327 laps. Ralf Kelleners, teamed with Yannick Dalmas and Emmanuel Collard, escaped unhurt.

Minutes later, a McLaren F1 GTR, running fourth, also caught fire.

``I got out of there very quickly,'' said driver Andrew Gilbert Scott.

McLaren F1 GTRs finished second and third. Pierre Henri Raphanel and Anders Olofsson shared the car that was second, about two laps down at the end. Peter Kox, Roberto Ravaglia and Frenchman Eric Helary were third.

Only 17 of 48 starters finished.

Andretti, son Michael, a current Indy-car star, and Frenchmen Olivier Grouillard were teamed in a Courage Porsche.

Andretti's car was in 18th place, but had problems early. It was in the pits twice for more than 1 1/2 hours before the race was six hours old. It's run ended Sunday morning, when Andretti left the course after 197 laps.

``The first time out the rear wing broke and I spun off,'' Andretti said. ``Then, down the Mulsanne straight the left front tire came off.''

He got the car back to the pits, but there it stayed.

The elder Andretti finished second two years ago, three minutes behind, after losing a half-hour in the pits following a spinout four hours into the race.

Last year he struggled to a 13th-place finish.

The two Andrettis have run before together at Le Mans, even adding another when John _ Mario's nephew _ was part of the team that finished sixth in 1988.