Last year, both BMW driver Marco Wittmann and Audi stalwart Mattias Ekstrom ran in Red Bull's famous blue livery, but Ekstrom's decision to quit the series has caused the Austrian company to reconsider its plans.

Ekstrom has had Red Bull's backing since 2002, and will continue to enjoy an association with the Austrian firm this season with his Audi-backed EKS team in World Rallycross.

It means the upcoming DTM season will be the first with no Red Bull-liveried cars on the grid since 2001, with BMW having already revealed a new livery for Wittmann based on its traditional 'M' colours.

Red Bull stressed the move was a "time-out but not a complete withdrawal", adding that "at the end of the year, when the future of DTM is clear, we will re-evaluate the situation."

Another Austrian sponsor, BWT, has also confirmed it will not return to the DTM this year.

Last year, the water company sponsored Mercedes duo Lucas Auer and Edoardo Mortara, who both ran the pink livery made famous by BWT's recent tie-up with Force India in Formula 1.

As well as Force India, BWT will sponsor F2 squad Arden and the Lechner Porsche Supercup team this year. Lechner will also sport BWT branding in the German Carrera Cup series.

Like Audi, Mercedes has yet to officially unveil its full range of 2018 DTM liveries.

Additional reporting by Gerhard Kuntschik