BMW's Bruno Spengler will call time on a 15-year DTM career to switch to the IMSA SportsCar Championship in 2020, but will remain with the manufacturer.
Spengler notably won the DTM title in 2012 - his first season with BMW, which was also its first year back in the series after an 18-year absence - and he has since contested 195 DTM races, winning 16.
His last victory came at the Norisring earlier this year, with Spengler one of only three BMW drivers to win during a difficult 2019 campaign that has led the manufacturer to review its setup - including its driver line-up.
Spengler will now race for BMW Team RLL in an M8 GTE and joins the IMSA programme following a trying season in the category for BMW.
It won the season-opening Daytona 24 Hours but then ended the campaign fourth and last of the full-time manufacturers in the GT Le Mans class.
"Firstly, I am obviously disappointed that I will no longer be racing in the DTM in 2020," said Spengler.
"I had a fantastic time for 15 years, during which time the DTM became part of my family. I have been racing in the DTM for almost half of my life.
"In my 195 races, I have enjoyed some fantastic success - above all, of course, my title win with BMW at Hockenheim in 2012.
"This title win will forever be very closely linked to Charly Lamm for me. As a sportsman, I would obviously have liked to have stuck around for a few more years.
"I would like to take this opportunity to thank all my mechanics and engineers who I have worked with all these years, and with whom I have celebrated so many successes.
"Even though it has come as something of a surprise to me that I won't be contesting my 16th DTM season, I'm looking ahead.
"I feel right at home in the BMW family, I am about to face a new challenge, and I am ready to write a new chapter in my career.
"I know the BMW M8 GTE, BMW Team RLL and some of the circuits in North America. As such, I think I will find my feet quickly there."
BMW has confirmed that Spengler will remain a reserve and test driver for BMW Andretti in Formula E.
Jens Marquardt, BMW motorsport boss, said: "Very few drivers have had as big an influence on the DTM as Bruno Spengler has in the past 15 years.
"In winning the title in his first season for BMW in 2012, he achieved something that nobody believed possible at the time.
"In doing so, he earned a permanent place in the history of BMW Motorsport.
"The fact that he broke the 1000-point mark in his 15th season in 2019 underlines the outstanding status that Bruno has earned for himself in the DTM.
"Nevertheless, we were of the opinion that 2020 is the right time to head in a new direction together for the coming years. This decision was not an easy one for us."
Spengler's exit leaves at least one space in the BMW factory line-up for 2020 and Marquardt has previously confirmed it will at least retain its six cars.
Ex-Williams Formula 1 driver Robert Kubica drove for BMW in the rookie test at Jerez, while factory driver Nick Yelloly also took part.