Shares in US-European car giant Stellantis, whose brands include Jeep, Fiat and Peugeot, plunged on Thursday after it published disappointing earnings while French rival Renault also tumbled despite record profitability.

Renault was down almost nine percent while Stellantis shed nearly eight percent in late morning deals, with both among the worst performers on the Paris CAC 40 index.

Stellantis, a 14-brand group that also includes Alfa Romeo, Chrysler, Dodge and Maserati, reported Thursday a 48-percent drop in net profit to 5.6 billion euros ($6 billion) for the first half of the year.

Its sales fell 14 percent to 85 billion euros.

The company was hit by falling sales in Europe and North America, and its sales and net profit were lower than expected by analysts polled by financial data firm FactSet and Bloomberg.

"The Company's performance in the first half of 2024 fell short of our expectations, reflecting both a challenging industry context as well as our own operational issues," Stellantis chief executive Carlos Tavares said in a statement.

Renault reported on Wednesday record profitability for the first six months of the year, with an operating margin, which compares operating profit to sales revenue, of 8.1 percent.

Its sale of shares in Japanese partner Nissan, however, caused its net profit to fall 38.2 percent to 1.3 billion euros.

Renault still holds a stake in Nissan, whose shares plunged more than 10 percent on Thursday after the company issued a profit warning, citing "intense sales competition", especially in the United States.