The DTM is in “final discussions” with Japan’s Super GT and is “very close” to a tie-up through Class One regulations, according to ITR boss Gerhard Berger.
The German tin-top series has remained in constant communication with Super GT over a planned transition to 'Class One' technical regulations, but those talks stalled when Mercedes announced its intention to quit the DTM in favour of Formula E at the end of 2018.
Audi stated Mercedes' departure would help the merge as it had previously voted against new engines designed as the first step towards 'Class One' back in 2017.
More recently, the DTM and Super GT conducted demo runs at Motegi and Hockenheim as the two series strengthened their ties to each other.
BMW and Audi both told Motorsport.com that an ongoing lack of clarity regarding regulations meant that manufacturers were reluctant to replace Mercedes, but Berger said that 'Class One' regulations were now close to fruition.
"We are in the final discussions about the regulations but I am very confident that we can find the solution," he told Motorsport.com.
"We also need international regulations, that means Japanese Super GT as an example, with us on the same regulations with the development costs for manufacturers as we want.
"We are very close to this."
When Motorsport.com asked BMW about a timeline for it to review its DTM participation, its director of motorsport Jens Marquardt hinted at a Super GT tie-up.
"Number one in that direction [of establishing a platform for newcomers] is the regulations, and to communicate them with Super GT," he said.
"I think we are that close towards that. That's the next step and then push on together to get a set-up for next year on the road."
When Motorsport.com approached Super GT for comment on a tie-up with the DTM, it provided a short statement.
"For the moment there is no decision. Regarding 'Class One', we, GTA [GT Association] and ITR are closely in discussions."
Motorsport.com understands that Audi and BMW would consider a bridging year with two manufacturers for 2019 if Class One is not finalised, while speculation of a GTE backup plan was shot down by Berger.
The DTM has continued discussions to replace Mercedes regardless, with Berger admitting to Motorsport.com he has spoken to every "premium" manufacturer in the pursuit of a third brand to join for 2019.