Italian automaker Fiat Chrysler Automobiles has moved higher in its first day of Wall Street trade after shifting its main listing from Milan to attract more investment.

The newly merged Italian auto giant, formed by Fiat's full acquisition of US automaker Chrysler, debuted on the New York Stock Exchange under the symbol FCAU.

It stood at $9 in morning trade, representing a 1.1% gain above its close on Friday when the world's seventh-largest automaker was trading on the NYSE as an American depositary share. 

The Wall Street market debut is not an initial public offering, rather it is the transfer of the main trading of the company's shares to the United States. 

Shares will continue to be traded in Milan but on the secondary market.

Fiat Chrysler Automobiles, headquartered in the Netherlands, became the holding company for the Fiat Chrysler Group on 12 October.

The company, whose brands include Fiat, Chrysler, Dodge, Jeep and Alfa Romeo, has operations in about 40 countries and its cars and trucks are sold in more than 150 countries.

For Fiat's chief executive Sergio Marchionne, the Wall Street launch marks a major milestone on his years-long effort to create a global automotive powerhouse.

Five years ago, Marchionne saw the opportunity to acquire ailing Chrysler, the third-largest US automaker, after it emerged from a bankruptcy reorganisation under the auspices of the US government, with the aim of boosting the prospects of both Fiat and Chrysler.

Fiat methodically acquired shares in Chrysler and completed the full acquisition in January 2014.

Along the way, the CEO's transatlantic vision was solidly backed by Fiat chairman John Elkann, despite concerns raised by the tie-up, especially in Italy.

Today’s stocks launch in New York, the world's financial capital, transfers the centre of gravity of the company to the United States, where markets are the most fluid and investors pockets are the deepest.

Marchionne has said he will conduct an investor "roadshow" in the coming weeks in the US to stump up interest in buying the stocks.