Net income slumped by more than half to 970 million euros  ($1.08 billion) in January-June as revenue fell 6.4% to 28.05 billion, the French carmaker said on Friday. Operating profit also dropped 13.6% to 1.654 billion euros.

"Given the degradation in demand, the group now expects 2019 revenues to be close to last year's," Renault predicted - abandoning an earlier pledge to increase revenue before currency effects.

A broad-based downturn has rattled the sector, prompting profit warnings and compounding challenges for Renault and Nissan as they struggle to turn the page on the Ghosn era. Their former alliance boss is now awaiting trial in Japan on financial misconduct he denies.

Renault's bottom line was hit by an 826 million-euro drop in earnings from its 43.4%-owned alliance partner. Nissan is cutting 12,500 jobs globally after an earnings collapse that it is keen to blame on Ghosn's leadership.

But Renault's own performance - reflected an operating margin that declined to 5.9% from 6.4% - contrasts less favourably with domestic rival PSA Group. The Peugeot maker defied the downturn with a record 8.7% profit margin unveiled on Wednesday.

Renault blamed falling sales in France, as well as Turkey and Argentina, for a 7.7% revenue drop at its core automotive business - whose profit margin slid to 4% from 4.5%.

Operating free cash flow also suffered, coming in at a negative 716 million euros as investment jumped by 742 million euros to 2.91 billion euros. The company nonetheless reiterated pledges to deliver positive full-year cash flow and a margin close to 6 percent.