German luxury carmaker Porsche AG reported a 34% rise in first-half operating profit to €1.35 billion on Wednesday, despite lower revenue and a double-digit decline in vehicle deliveries. Once Volkswagen's most reliable source of profit, Porsche has been hit especially hard by slumping Chinese demand for German luxury cars and weaker-than-expected electric vehicle sales. The German sports-car maker attributed the increase in profit to tighter management of costs, prices and its product mix, alongside its "value over volume" strategy. "Over the past six months, the Porsche team has worked very intensively and with great discipline on our strategy. Despite this, Porsche expects its full-year revenue to come in between €35bn and €36bn.