Volkswagen Group has ended a partnership with Aurora Innovation, the autonomy startup founded by former Google self-driving head Chris Urmson, as was first reported by the Financial Times. Aurora was supposed to provide Volkswagen with a full tech stack it calls the “Driver,” which would enable completely autonomous cars, not a driver assistance system (like what’s available on Audi’s cars).

Volkswagen was one of Aurora’s first customers. The two companies announced the deal at the 2018 Consumer Electronics Show, though they had been working together for at least a year before that. The deal was supposed to end this June, according to two people familiar with the terms, and Volkswagen declined to sign a new one.

To keep its self-driving efforts moving forward, Volkswagen is reportedly pursuing a new deal with Ford-backed startup Argo AI. Volkswagen and Ford announced a “global alliance” in January that’s centered on trucks and vans, though both companies said collaborations on electric and autonomous vehicles were possible. Volkswagen was also rumored to be investing nearly $2 billion in Argo earlier this year, though no deal has gone through. (It also reportedly tried to buy Aurora last year.)

Volkswagen announced a “global alliance” with Ford in January

“From Volkswagen’s perspective, it would make a lot of sense to cooperate with an American player given that the regulatory conditions for preparing the breakthrough of autonomous driving are more advanced in the US than they are in Europe,” Volkswagen CEO Herbert Diess said about the tie-up with Ford.

News of the split comes just a few days after Fiat Chrysler announced it will pay an undisclosed amount of money to use Aurora’s tech to power self-driving commercial vehicles. Hyundai and EV startup Byton are also Aurora customers, and the self-driving tech company raised half a billion dollars earlier this year in a funding round led by Amazon.

A spokesperson for Aurora would not confirm the split, but the company said the deals with Hyundai and Byton are still in place. “Volkswagen Group has been a wonderful partner to Aurora since the early days of development of the Aurora Driver,” the spokesperson said in a statement. “As the Driver matures and our platform grows in strength, we continue to work with a growing array of partners who complement our expertise and expand the reach of our product.”

Argo was co-founded by Bryan Salesky, another former member of the Google self-driving team. He was also on the same team as Urmson in the 2007 DARPA autonomous vehicle challenge, which is seen as a watershed moment in the pursuit for self-driving cars. Ford dumped $1 billion into Argo in 2017 and has worked closely with the startup ever since.

While both companies are still in the developmental phase, Argo is ostensibly a direct competitor to Aurora, in that it’s trying to develop and sell the full technology suite that would power future self-driving cars. Others, like GM’s Cruise, are trying to develop self-driving tech alongside a purpose-built car.

During an interview on The Vergecast in April, Urmson talked about how he views competition like Argo. “We don’t think there’ll be many, many people who can do this. We think actually building the driver is really hard,” he said. “We imagine what’s now around 100 companies working in this space will probably consolidate down to a handful, and we expect to be one of those companies.”