Delta Air Lines Inc. (DAL) said Monday its international passenger traffic fell 15.1% in March, far worse than declines seen by its largest rivals.

The Atlanta-based carrier is continuing to roll out targeted expansion of its overseas network, but suffered larger year-on-year declines on transatlantic and Latin America services than American Airlines and Continental Airlines Inc. (CAL).

Delta is the largest U.S. operator across the Atlantic, and business fell 13.9% last month, measured in revenue passenger miles. This compares with an 8.8% fall at Continental and a 12% drop at American, a unit of AMR Corp. (AMR).

The performance on Latin American routes was even worse, with Delta off 17% in March. American, the market leader in services to and from the region, suffered a 14% decline and third-ranked Continental was down 4.8%.

Its transpacific business, largely inherited from merger partner Northwest Airlines Inc., was down 16% in March.

Delta did not provide guidance on revenue trends. Continental said last week that passenger revenue fell by almost 20% in March, driven by the industrywide decline in premium traffic.

Atlanta-based Delta's mainline domestic traffic fell 13.3%, while capacity dropped 11.2% as it joined other carriers in trimming unprofitable schedules and parking or returning aircraft.

Overall, Delta's passenger traffic was down 12.6% while capacity fell 7.9%.

Delta shares were up 3% at $6.84 in late session trading.

-By Doug Cameron, Dow Jones Newswires; 312-750-4135; doug.cameron@dowjones.com