The German moves across from Porsche’s sister marque Audi, which will withdraw from endurance racing at the end of 2016, ending a six-year association with the Ingolstadt manufacturer that has yielded three Le Mans 24 Hours victories and the 2012 WEC title.

Motorsport.com understands that Lotterer had been in talks with both Toyota and Porsche about a 2017 LMP1 drive before ultimately deciding to take up an offer from the latter.

Nonetheless, Lotterer is set to stay connected to Toyota in 2017 after agreeing to remain at the TOM’S Super Formula squad alongside Toyota WEC driver Kazuki Nakajima.

It remains to be seen exactly where Lotterer will slot into the existing Porsche line-up, but with Nick Tandy also being added to the team’s 2017 roster, it signifies that at least one other driver will be forced to make way along with the retiring Mark Webber.

Marc Lieb in particular is thought to be highly unlikely to retain his place, while Romain Dumas may also be vulnerable, with Earl Bamber still believed to be in contention to make the step up from Porsche’s GT ranks like his Le Mans-winning teammate Tandy.

Other Audi drivers still face uncertain futures

While Lotterer has found a home for 2017 with a rival LMP1 manufacturer, the situation looks less certain for Audi’s other five existing drivers.

Their chances of staying on the WEC grid full-time are lessened by the fact that Toyota is believed to have already signed off on its primary 2017 driver line-up, with Jose Maria Lopez set to replace Stephane Sarrazin.

However, there remains a strong possibility that the Japanese manufacturer will field three cars at Le Mans next year, a move which could prompt Porsche to respond by entering a third car of its own at La Sarthe – and therefore open up more opportunities for Audi’s current drivers to return.

“There are a lot of possibilities, but there are so many ‘ifs’ also,” Loic Duval told Motorsport.com on his prospects of staying involved in WEC next season.

“For a constructor in LMP1 there are lots of positives in having an experienced driver. I have to look at the opportunities, but at the moment there is too much fog.”

Read Also: The state of play in the LMP1 driver market

Lucas di Grassi meanwhile says his main focus will be on his Formula E commitments with Audi going forward, but isn’t ruling out a Le Mans return if the right opportunity arises.

He said: “Formula E is coming up as a replacement for WEC, and I will take on this challenge full-time, as a works driver, and try to represent the four rings in the same way I did in WEC.

“I’m only 32, and I feel I can still come back. If another company in the [VW] Group or another company decides to do LMP1, I will happily come back to do Le Mans.

"It would be a great race to do in parallel with my Formula E programme next year.”

Oliver Jarvis and Benoit Treluyer are also candidates to drive third cars at either Porsche or Toyota, while Marcel Fassler could take on a larger role in the Corvette GT squad, with which he contested the Daytona, Sebring and Petit Le Mans enduros this season.

“First we will have a meeting with Audi, then decide what possibilities there are for me within the group,” said Fassler in Shanghai. “I’m pretty open to everything at the moment.

“For sure the contact [with Corvette] is there, I was there in 2009 [at Le Mans] before I went to Audi, and involved this year also in some races. But nothing is decided yet.”

Additional reporting by Kunihiko Akai and Sam Smith