METZINGEN, Germany — Hugo Boss ​Chief Executive Claus-Dietrich Lahrs is stepping down after eight years at the helm of the German fashion house after the share price tumbled following a profit warning on weak sales in China and the United States.

Hugo Boss shares fell to their lowest level in five years on Tuesday and Wednesday after the firm said it expects sales to grow more slowly than its long-term forecast in 2016 and adjusted operating profit to fall.

Boss said Bernd Hake, currently responsible for the Europe, Middle East, Africa and India regions, would take responsibility for sales and retail as a new member of the managing board from March 1.

Lahrs' other responsibilities would be taken on by other members of the board until a successor is found.

By Emma Thomasson; editor: Maria Sheahan.