American-US Airways deal will impact competitors

Alaska has strong links to Delta, which helps feed traffic into Alaska's Seattle hub. Alaska's core territory is for flights up and down the West Coast, and even the merged American will still trail Delta and United in that part of the country.

SPIRIT AIRLINES INC.

The low-cost airline will now face stronger competition on its lucrative Caribbean routes. However, it is aggressively expanding into large cities like Houston, Orlando, Detroit, Denver and Dallas. If American, Delta, Southwest and United raise fares in those cities, more passengers might flock to Spirit.

VIRGIN AMERICA

The airline has a heavy debt load and loses money. It is struggling to lure business travelers, and this merger will probably make that task even harder. However, more leisure travelers who are looking for an alternative flying experience might be attracted to Virgin.

ALLEGIANT TRAVEL CO. and FRONTIER AIRLINES

These two airlines have focused on smaller cities that have trouble attracting larger airlines. If routes now served by American and US Airways are dropped, these two carriers could take advantage of the vacuum.