KENNER — Louisiana’s major airport has started off 2012 with an increase in passenger traffic over the year.

Louis Armstrong New Orleans International Airport had 661,584 passengers in January compared with 643,021 in January 2011.

The number of passengers leaving the airport on domestic, international and charter flights rose to 328,744 from 321,970 in January 2011.

The passengers arriving at the airport rose to 332,840 from 321,051.

Among domestic carriers, Southwest Airlines Co. led all airlines in January with nearly 33 percent of all passengers.