McLaren has lured one of Williams's long-time sponsors away, after signing a multi-year technical partnership with Unilever from the start of the 2020 Formula 1 season.
Unilever had been with Williams since 2015, and had used its F1 involvement with the outfit to promote its Rexona brand.
But as its Williams contract is coming to an end, the consumer brand has elected to move to McLaren, which finished an encouraging fourth in the constructors' championship in 2019.
As part of the deal, between McLaren and Unilever will work together on projects that includes areas such as material science, sensor technology and the creation of an engineering academy.
McLaren CEO Zak Brown has been close to Unilever for many years, and his previous company JMI helped broker Unilever's deal with Williams and an earlier one with the Lotus team.
Dave Penrith, chief engineer at Unilever said: "This is a very exciting partnership for both Unilever and McLaren.
"Together we will use our combined efforts to solve both current and future challenges with some of the best engineering minds in the world, and also develop the next level of talent within our companies."
The Unilever company has around 400 brands, including Dove, Knorr, Rexona, Hellmann's, Wall's, Magnum and Axe.
In a Tweet, Williams said it wished Unilever well after their long-standing partnership.
Earlier this week, Williams announced an extended partnership for the 2020 season with Canadian food manufacturer Sofina Foods, the company that was founded by driver Nicolas Latifi's father Michael.
The company's logo will appear on the rear wing of the Williams F1 car as well as team wear and driver overalls.
Williams has also announced a new deal with Italian coffee company Lavazza, which has been a long-time backer of Latifi.