The double-clutch gearbox will be deployed in so-called "mild" hybrids that combine a 48-volt electric motor with a combustion engine, the Peugeot maker has previously said.

The joint venture with Chinese-owned Punch will create 400 jobs at the carmaker's Metz plant as it targets annual production of 600,000 gearboxes within four to six years, the Force Ouvriere union official told Reuters.

A PSA spokesman said the company had no immediate comment.

(Reporting by Laurence Frost)