PSA is buying Opel in a deal valuing GM's European arm at 2.2 billion euros ($2.33 billion), creating a new car giant in the region to challenge market leader VW.
"Opel and PSA will have had their reasons" for the transaction, Mueller told Reuters late on Monday on the eve of the Geneva auto show. "It has no influence on our plans initially. We have our own ideas and thoughts and will thoroughly work with them."
Asked whether the VW brand will face greater competitive pressures after PSA, by acquiring Opel, becomes Europe's second-ranked carmaker by sales, Mueller said: "We took Opel and PSA seriously as competitors in the past. These were two brands and now they're under a single roof. I don't believe that a great deal will change there."
The VW brand and PSA-Opel will be competing in a European market that analysts have said will become even tougher as emissions rules tighten, demand is near its peak and young customers turn to ride-hailing services rather than buying a car.