A merger between Fiat Chrysler and France's PSA Group won approval from both sets of shareholders on Monday.
The deal will create the world's fourth biggest carmaker and comes two years after talks began.
The combined company will bring together well-known brands such as Peugeot, Citroen and Vauxhall from PSA with Fiat, Jeep and Chrysler.
The new company following the $52bn (£38bn) deal will be called Stellantis.
Stellantis, which means to brighten with stars, will have 14 car brands under one roof including niche players Maserati and Alfa Romeo.
Executives expect the merger to be finalised by the end of March and say it will provide significant cost savings.
This has raised concerns about the closure of some factories across the brands, including those of Vauxhall which employs 3,000 people in the UK.
However, in November PSA pledged not to close factories after the merger even though the combined group would have spare production capacity of almost six million cars.
Source: BBC