WASHINGTON (Reuters) - Delta Air Lines Inc sued the Export-Import Bank of the United States on Wednesday, renewing a legal fight over subsidies that benefit aircraft exporters such as Boeing Co and by extension non-U.S. airlines. The suit was filed in U.S. District Court in Washington, D.C. Joining Delta as plaintiffs were Hawaiian Airlines Inc and the Air Line Pilots Association, International. (Reporting by David Ingram; Editing by Gary Hill)