FILE PHOTO: The logo of PSA Peugeot Citroen is seen at the company's plant in Poissy, near Paris, October 31, 2019. REUTERS/Charles Platiau

MILAN (Reuters) - A planned merger between Fiat Chrysler and Peugeot owner PSA PEUP.PA would only benefit shareholders, two of the biggest Italian and a French unions said on Thursday, criticising a decision not to include labour groups in the decision.

“The decision by FCA and PSA to start negotiations to merge the two groups without any involvement of, or communication to workers and union representatives is unacceptable,” France’s CGT and Italy’s Fiom-Cgil unions said in a joint statement.

Fiat Chrysler and PSA on Thursday announced a plan to join forces in a 50-50 share merger to create the world’s fourth-largest automaker, seeking scale to cope with costly new technologies and slowing global demand.

As things stand, the deal would produce positive results just for the two companies’ investors and financial markets, CGT and FIOM said. The two labour groups said they would work together to safeguard jobs as well as research, development and production capacity in Europe.