DOW JONES NEWSWIRES U.S. airlines carried 2.2% more passengers in March than a year earlier, though increased airline capacity left planes less full, the Department of Transportation said Thursday. March represented the 14th-straight month of growth in passenger counts over their prior-year levels, reflecting an ongoing recovery in demand for air travel. Airlines have widely benefited from the uptick in business and added capacity in response, though mounting fuel costs are pressuring their bottom lines. The DOT's Bureau of Transportation Statistics said airlines carried 63.6 million scheduled passengers in March. Traffic, in terms of revenue passenger miles, increased 2.7%. Load factor, a measure of plane fullness, fell to 80.7% from 82.7% as capacity was 5.1% higher. Delta Air Lines (DAL) and Southwest Airlines Co. (LUV) again carried the most total and domestic fliers, respectively. AMR Corp.'s (AMR) American Airlines was the top international carrier. Among airports, Hartsfield-Jackson Atlanta International again led in total passengers, while Miami International saw the most international fliers board. -By Drew FitzGerald, Dow Jones Newswires; 212-416-2909; Andrew.FitzGerald@dowjones.com