Last year's DTM runner-up Edoardo Mortara has been confirmed in the Mercedes driver line-up while Maro Engel makes a return to the Germany touring car series after a five-year absence.

In the regular DTM line-up shuffles, Mortara - who has spent the past six years with Audi - switches forces to join Mercedes while the other new addition to the line-up is Engel who returns to DTM from GT racing for the first time since 2011.

Robert Wickens, Gary Paffett, Paul Di Resta and Lucas Auer have all been retained by Mercedes in the DTM driver squad for 2017, while last year's European F3 runner-up Maximilian Gunther has been made reserve and test driver.

With the reduction in driver numbers on the DTM grid for 2017, Christian Vietoris, Daniel Juncadella, Maximilian Gotz and Felix Rosneqvist have been dropped.

After seeing Pascal Wehrlein crowned 2015 DTM champion Mercedes endured a difficult 2016 campaign finishing last in the manufacturers' championship and its best placed driver, Robert Wickens, finished fourth in the drivers' championship.

Head of Mercedes-AMG DTM Ulrich Fritz accepts it will be another challenging campaign but has full confidence his six-driver line-up has the quality and experience to produce the results required.

"In 2017, all of us manufacturers will be up against major challenges. We have a new car, new tyres and a reduction in the number of drivers on the grid," Fritz said. "The standard of competition is therefore going to be higher than ever before in the DTM. That's precisely why I am glad we have put together such a high-calibre squad. Edo, Lucas, Paul, Gary and Rob have all won DTM races and are well capable of having a say in the destination of the title.

"But therein lies yet another major challenge for the team and the drivers - to succeed this year, we need to function as a homogenous and resolute unit. Added to which, we have Maro who also has a lot of experience and is a title winner in his own right."

The first pre-season test begins at Portimao on the 20-23 February before further tests at Vallelunga on the 13-16 March and Hockenheim on the 3-6 April. The German circuit hosts the traditional DTM curtain raiser on the 5-7 May.

"There is still a lot of work to be done before the season gets underway," Fritz said. "We have to continue developing our new car and get used to the new regulations. However, I am confident that, with our team setup, we are well equipped to have a successful season."