By Nate Raymond (NS:) and David Shepardson (Reuters) -A U.S. appeals court on Friday held that a trial judge correctly found that American Airlines (NASDAQ:)’ now-scrapped U.S. Northeast partnership with JetBlue Airways (NASDAQ:) violated federal antitrust law. Siding with the U.S. Department of Justice, the Boston-based 1st U.S. Circuit Court of Appeals affirmed a trial judge’s ruling blocking the airlines’ “Northeast Alliance,” which had allowed the two carriers to coordinate