Williams has announced that Toto Wolff is to leave his role as an executive director of the team with immediate effect to take up a new position with Mercedes-Benz.
As AUTOSPORT reported on Sunday night, Wolff is set to take up a senior management position in charge of Mercedes-Benz's motorsport activities as replacement for the departed Norbert Haug.
As a shareholder and director at Williams, the new job would have led to a clash of interests, which is why he has stood down from his direct responsibilities with the outfit. He will retain his financial involvement, however.
Team principal Frank Williams praised the work that Wolff had done for his Grove-based outfit over recent years, and said it would have been wrong to stand in the way of the opportunity the Austrian had at Mercedes.
"I would like to thank Toto for his hard work, dedication and commitment to the team during his time as one of our executive directors," explained Williams.
"He was a key support to me in this role last season, deputising at a number of races when I was unable to attend. However, positions such as the one offered to him by Mercedes do not come around often.
"Toto has a long history with them and I certainly was not going to stand in the way of him accepting this once in a lifetime opportunity.
"Toto will retain his shareholding in Williams and will always have a place at Grove but make no mistake; we will fight him hard on the race track!
"I am sure he will be a strong asset for Mercedes and on behalf of the whole team I would like to wish him the best of luck in his new role."
Wolff already had close ties with Mercedes through a 49 per cent stake he had in the engineering company HWA, which helps run the German car manufacturer's DTM programme.
Wolff's departure from Williams comes against the backdrop of other senior staff having left the outfit over the past year, including former chairman Adam Parr and chief operations engineer Mark Gillan.
Williams said that he had confidence the current management structure of the team would continue to ensure that the outfit had a bright future.
"I'm lucky to have a very professional group of people around me and the company's executive committee will continue the work they have been doing to ensure a successful future for the business," he said.
Williams looks set to be the only team to miss getting its cars ready for the first pre-season test at Jerez in Spain, however. Its new challenger will be launched before the second test in Barcelona.