The negotiations that melded Fiat Chrysler and PSA into Stellantis were a postgraduate-level education in efficiency, diplomacy, and thinking outside the box, according to lawyers involved in the deal.

Fiat Chrysler, based in Italy, and PSA, the French-based maker of Peugeot, Citroën and Opel cars, completed their merger of equals in January, just a year after agreeing on the terms of the deal in December 2019.