Nearly 10 months after Fiat SpA bought the rest of Chrysler Group LLC from a union trust, the two companies are now officially one, headquartered in London with operations in Auburn Hills, Michigan, and Turin, Italy. The move caps a years-long rescue of the 89-year-old U.S. automaker that fell into bankruptcy in 2009, costing U.S. taxpayers $1.3 billion.

FCAU, as the company’s New York Stock Exchange ticker symbol is known, was dragged down nearly 1 percent by a selloff in the market, to close at $8.92 a share Monday. FCA is now the world’s seventh largest auto company, and its listing in New York is a way to access a more affordable source of funding from the world’s biggest equity market.

CEO Sergio Marchionne joined FCA Chairman John Elkann, whose family retains significant control over Fiat, to ring the stock bell in New York Monday.

Marchionne and Elkann have tried to emphasize the company remains American and deliberately chose Columbus Day as a symbol of Chrysler’s all-American roots. FCA sells half of its cars in the U.S., a market vital to the company’s five-year plan to boost sales by 60 percent, to 7 million vehicles, and a 500 percent increase in net profit, to $6.9 billion.

Fiat helped rescue Chrysler from insolvency in 2009 and in January completed a $4.35 billion purchase of 41 percent of Chrysler from a United Automobile Workers retirement benefits trust. Fiat will pay the trust $700 million a year through 2018 as part of the deal.