BMW driver has competed in the DTM since 2013 and has seen the series turn towards an international future, most notably by linking up with Japan's SUPER GT through the Class One regulations.
Motorsport.com understands that a name change for the series is still under consideration, having first been mooted during the 2018 season.
Wittmann told Motorsport.com that he believes a name change could help it attract manufacturers to add to Audi, BMW and the R-Motorsport Aston Martin team.
"I’m fully behind this [international] way because in general, I think the DTM has the name that says German touring car championship," said Wittmann.
"But the series is so professional and actually, in the end, everybody knows the DTM is the second-best championship worldwide next to Formula 1.
"The name 'German touring car championship' is not big enough. For me, international is the way to go and to attract more manufacturers, to be honest.
"For Audi and BMW it’s great to race in Germany, we are super-happy that Aston Martin stepped in, but we want to attract other manufacturers. I think you have to go more international. It maybe does not need to go worldwide, but more international."
Marco Wittmann, BMW Team RMG, BMW M4 DTM