Alaska Air Group ( ALK) said Friday that February passenger traffic for its Alaska Airlines unit increased 6.4% to 1.26 billion revenue passenger miles. Alaska's capacity during February increased 2.1% from the same month a year ago to 1.71 billion available seat miles. The passenger load factor for the month was 73.7% compared with 70.7% in February 2005. Traffic at Alaska's Horizon Air division rose 19.7% last month to 195.3 million revenue passenger miles. Horizon's capacity during February increased 12.8% to 273.2 million available seat miles. The passenger load factor for the month was 71.5%, up from 67.4% last year. Shares of Alaska slipped 28 cents to $30.96.