Daimler has no plans to increase its Aston Martin stake or become involved in operational matters at the UK sports car maker, Daimler CEO Dieter Zetsche said.

The huge difference in size between the two companies is one reason why Daimler won’t get involved in running Aston Martin, Zestche said.

Daimler sells more than 1 million Mercedes-Benz cars a year while Aston Martin’s annual sales volume is much smaller.

“I don’t think we could do a better job running a 4,000-units-a-year company than Aston Martin’s management,” Zetsche said on the sidelines of a press event here.

Daimler has a 5 percent stake in Aston Martin that it got in exchange for supplying the company with electric and electronic parts and V-8 engines from Mercedes’ AMG performance unit. Zetsche said no cash changed hands in order for Daimler to get its share.

Reports have said that Daimler and Aston Martin are also in talks on using Mercedes technology to develop an SUV that Aston Martin that would go on sale in 2017.

In December 2012, Italian tycoon Andrea Bonomi’s Investindustrial bought 37.5 percent of Aston Martin in a $241 million deal with Kuwaiti controlling shareholders Investment Dar and Adeem Investment.

Zetsche said Investindustrial believed that Aston Martin needed a technical partner to help secure its long-term future. “As we share this vision, we were willing to be their technical partner,” he said.

Nissan’s former chief planning officer, Andy Palmer, became Aston Martin CEO on Oct. 1. He is tasked with upgrading the brand’s aging product lineup and almost doubling Aston Martin’s annual sales volumes to 7,500 cars by 2018 from 4,200 last year.