MILAN — Fiat Chrysler and PSA shareholders are scheduled to meet on Jan. 4 to approve their planned merger and create Stellantis, the world’s fourth biggest car maker, the two companies said on Wednesday.

In December, Italian-American Fiat Chrysler Automobiles and French Peugeot maker PSA agreed to combine in a $38 billion all-share deal, uniting brands such as Fiat, Jeep, Dodge, Ram and Maserati with the likes of Peugeot, Opel, Citroen and DS.

The two companies have pledged to finalize the merger by the end of the first quarter of next year.