American air carriers United and Continental officially announce a merger that will create the world's largest airline. [http:--money.cnn.com-2010-05-03-news-companies-United_Continental_merge-index.htm?source=cnn_bin&hpt=Sbin (CNN)] [http:--preview.bloomberg.com-news-2010-05-03-united-continental-fliers-will-see-more-hubs-higher-fares-after-merger.html (Bloomberg)]date=April 2020