Shares in Peugeot fell 6% in morning trade on Friday after the company reported a 13% fall in first-half sales.
The French car company is considering a new round of cost-cutting measures which could include closing a factory.
Worldwide sales fell to 1.62 million vehicles in the first six months of this year, compared with 1.86 million in 2011.
The company said in a statement that the eurozone debt crisis was having a marked effect:
''The Peugeot and Citroen brands' traditionally strong markets, France, Spain and Italy, are in profound crisis.''
European sales fell by 15%.
The BBC reports the announcement sparked falls in shares of other major carmakers and their suppliers.
Shares in BMW and Daimler were down by 3%. Michelin was down 1.5%.