TURIN (Reuters) - Fiat Chrysler CEO Sergio Marchionne complained on Thursday about emissions regulations in the European Union, saying that the single market was meant "to avoid this mess".

"Bad rules are also applied in a different way in every country, creating the worst solution that could be invented," Marchionne said.

FCA faces a U.S. criminal investigation for alleged emissions manipulation and German accusations that it, like VW, used "defeat devices" to confound nitrogen oxide (NOx) tests.

The Italian-American group on Monday also became the third carmaker after VW and Renault to be referred to French prosecutors over the scandal. FCA has denied breaking any laws.

(Reporting by Gianni Montani; writing by Francesca Landini)