The German company said 4.2 billion euros in one-off expenses contributed to the operating loss in the quarter, compared with a 2.6 billion profit in the same period last year.

"In general, we are intensifying the group-wide performance programs and reviewing our product portfolio in order to safeguard future success," Chief Executive Ola Kaellenius said in a statement on Wednesday.

For Daimler, the pressure to clean up combustion engines has come at a time when the industry has to invest heavily in electric and self-driving vehicles, and cope with slowing growth in China, weak markets in Europe and a rise in global trade tensions.

Passenger car sales slowed 3% during the quarter and the return on sales at Mercedes-Benz Cars swung to a negative 3% in the quarter, down from 8.4% in the year-earlier period.

Earlier this month, the Stuttgart-based car maker pre-released earnings in what amounted to its fourth profit warning in 13 months, saying its 2019 group EBIT would be "significantly" lower than last year.

Daimler said it expected unit sales of Mercedes-Benz Cars and Vans to stay at the prior-year level, thanks to increased product momentum in the second half. Sales of trucks and buses are expected to rise, the company said.