Marcel Siem of Germany has extended his lead to four shots at the Trophee Hassan II with a three-under 69 in Saturday&aposs third round. Siem leads Spain&aposs Pablo Larrazabal, David Horsey of England and Finland&aposs Mikko Ilonen, who all share second position on 11 under, while Austria&aposs Bernd Wiesberger is fifth at the Golf du Palais Royal, two shots further back. With a round to play in the Moroccan city of Agadir, Siem is on track for his first European Tour victory since the Alstom Open de France in July last year. The 32-year-old German started his third round badly with a bogey on the first hole but four birdies in six holes from the seventh onward saw Siem build some momentum. And despite a bogey on the 17th, he can be happy with his efforts in the penultimate round. Horsey and Ilonen both missed out on chances for outright second with bogeys on the 18th hole seeing them each card two-under 70s, while Larrazabal birdied three of his last five holes to score a three-under 69 around the course situated inside the royal palace in Agadir. With one round to play, Scotland&aposs Craig Lee, who is sixth, already looks off the pace at eight under, seven strokes behind Siem. There are three players who are two shots behind Lee in Sweden&aposs Mikael Lundberg, Matthew Baldwin of England and Spaniard Alvaro Velasco. Scott Arnold is the best-placed Australian on four under, on shot behind Lundberg, Baldwin and Velasco, while Richard Green is on two under in a tie for 20th.