Automakers need to introduce electric vehicles to meet increasingly stringent emissions-reduction regulations in Europe and China. “We are still far away from meeting the 2021 target,” Mr. Diess said, referring to the European benchmark.

The need for companies to share the cost and risk of developing autonomous vehicles has become more urgent because car sales are slowing in all major markets, including China, the United States and Europe.

“The financial investment is immense, and yet we don’t know when they will be in the marketplace or how they will make money,” said Michelle Krebs, a senior analyst at Autotrader. “It’s not just the money. The talent pool for people developing these vehicles is small.”

Profits are falling across the industry. Daimler said Friday that it would report a pretax loss for the second quarter of €1.6 billion. A year earlier, Daimler reported a profit of €2.6 billion.

The company, based in Stuttgart, Germany, said the loss was caused by the need to set aside €1.6 billion related to investigations in the United States and other countries into whether Mercedes diesel cars were equipped with software to evade emissions standards. In addition, Daimler will set aside €1 billion to cover the cost of recalling cars with defective airbags made by Takata, a Japanese company.

Other big carmakers have already formed partnerships to develop cars that can drive themselves. Cruise, General Motors’ autonomous division, has received billions of dollars in financing from Honda and others. G.M. has put Cruise’s valuation at $19 billion.

Toyota has teamed up in autonomous vehicles with Uber, the ride-hailing service. The luxury carmakers Mercedes and BMW have pooled their self-driving efforts. Several large automotive suppliers are also working on autonomous technology.