Daimler chief Dieter Zetsche has no plans to hand over control of the car business any time soon.

The 58 year-old chief executive told Reuters he was not looking to groom a successor at Daimler’s core Mercedes-Benz business even though some investors are said to be frustrated with the brand’s underperformance compared with other German carmakers.

Zetsche said his dual role at Daimler and Mercedes increased his effectiveness. “I am convinced that I would be a considerably worse CEO of the group if I wasn’t deeply anchored in its operating business.”

Reuters noted that, although shares in the car and truck business have risen 27% since the start of 2009, stock in German rival rival BMW has more than doubled.

Zetsche’s contract runs to the end of 2013. The former Chrysler boss was first appointed head of Daimler in July 2005 and given responsibility for Mercedes by the company’s board the following month after then-chief Eckhard Cordes decided to leave.

Zetsche added: “I would also be much worse a Mercedes chief if I didn’t have the opportunity to shape its fortunes directly and with all consequence and determination.”

Analysts believe Daimler’s management has repeatedly fallen short of market expectations and has clung to an inefficient conglomerate structure.

Zetsche said he did not favour any one candidate to replace him one day at the helm of either Mercedes or Daimler.

“We have no crown princes. I have six boardroom colleagues here that all do an excellent job performing their respective duties. No considerations have already been made about when this question (about succession) will become an issue and certainly no decisions – even less has there been any deliberation made about how,” he said.

With an operating margin of nearly 9.4% in the first nine months, Reuters said that Mercedes lagged behind equivalent returns above 12% at BMW and Volkswagen -owned Audi.

The Daimler CEO said the performance of Mercedes had nothing to do with the additional burdens of his dual executive roles, pointing to other rivals like Martin Winterkorn, head of both the Volkswagen brand and group, as well as Renault-Nissan CEO Carlos Ghosn and Fiat-Chrysler CEO Sergio Marchionne.

He added: “It’s a positive development that a majority of those responsible in the auto industry also have an operational role and don’t just walk around as a mere figurehead.”