Chrysler Group saw big sales gains in the first quarter thanks to the new Jeep Cherokee and Ram pickup, but its results were overshadowed by charges related to its merger with Italian automaker Fiat SpA.

Chrysler lost $690 million US in the January-March period. Without one-time charges related to the merger, the company's net income more than doubled to $486 million.

In January, Fiat paid $3.65 billion to a union-run health care trust to acquire Chrysler's remaining shares. As part of the deal, Chrysler agreed to pay $700 million to upgrade its factories.

​Auburn Hills, Michigan-based Chrysler took a $672 million charge in the first quarter to meet those commitments. It also booked a $540 million non-cash loss on extinguishment of debt related to the merger.

Revenue rose 23 per cent to $19 billion.

Worldwide vehicle sales jumped 10 per cent to 621,000.

In the U.S., Chrysler's biggest market, the company's sales rose 11 per cent, far outpacing the 1 per cent average gain for the industry.

Chrysler saw strong sales of the new Jeep Cherokee SUV, which went on sale at the end of last year. Ram pickup truck sales were also up 25 per cent in the U.S.