* Loeb penalised five minutes for speeding
* Al-Attiyah takes third stage win in a row
* Peterhansel still leads car category (Adds Loeb 'rant' after time penalty)
Jan 6 (Reuters) - Sebastien Loeb, the world's most successful rally driver, slammed Dakar stewards after he collected a five-minute time penalty for speeding in Wednesday's fourth stage in Saudi Arabia.
The sanction dropped the Frenchman, a record nine-times world champion, from fourth overall to seventh.
"You've got to know me a little after all these years and only very rarely do I have a 'rant'. But this evening, I need to share with you the incompetence of the stewards' panel," he said on Instagram.
Loeb explained that an alarm had not sounded in the car when it entered a controlled speed zone due to a recognised GPS problem. He said the penalty was far greater than any time gained.
"I am passionate but above all I am a competitor. And today, if I am in a race like the Dakar, it is first and foremost to achieve what I am employed for: to achieve a result that meets the ambitions of the team and meets my ambitions," he said.
"And for that, there is no room for incompetence, nor for the incompetent."
Qatar's triple champion Nasser Al-Attiyah took his third stage win to chip away at Stephane Peterhansel's overall lead.
The Toyota driver was four minutes and 58 seconds adrift of Peterhansel, the veteran "Mr Dakar" who has won the event a record 13 times on two wheels and four but has yet to take a stage this year.
Despite his speed, Al-Attiyah clawed back only 11 seconds from the consistent X-Raid Mini driver who finished second on the 337km stage from Wadi Ad-Dawasir north to the Saudi capital Riyadh.
"We're not marking one another, it's just one relentless attack after another," said Peterhansel of the battle to stay ahead.
Spaniard Carlos Sainz, Peterhansel's team mate and the defending champion, climbed back to third overall but 36 minutes off the lead.
Dutch driver Bernhard ten Brinke retired after rolling his Toyota pickup heavily on Tuesday.
In the motorbike category, France's Xavier de Soultrait took the lead for Husqvarna with Spaniard Joan Barreda 15 seconds behind after winning the stage.
Argentina's Kevin Benavides was third, three minutes and nine seconds further back.
Russian Dmitry Sotnikov, in a Kamaz, took his third stage win in the truck category to extend his lead.