Seven time world champion Schumacher’s existing three year contract, dating back to his decision to return to F1 in 2010 after a three-year sabbatical, runs out this year.
Zetsche is quoted by Seddeutsche Zeitung newspaper as saying Mercedes is fully committed to formula one, with an “engagement for the long term”.
As for involving 43-year-old Schumacher in those plans for 2013, Zetsche admitted it was “an attractive possibility”.
“He is still a motor sports icon,” he added.
Schumacher said at the Jerez test this week that while he might not have a title-winning car this year, Mercedes will build one in the future.
“We have to build our way there. I’m confident we can do that, in future, but let’s take it step by step,” said the German.
As for the possibility of a new contract, Schumacher answered: “I never gave any prognosis about my career. The right time will come to discuss my future.”