April 22 (Reuters) - Wall Street’s main indexes opened flat on Thursday as investors assessed earnings from U.S. airlines and AT&T, while data showed fewer Americans filed fresh claims for unemployment benefits last week. The Dow Jones Industrial Average fell 27.43 points, or 0.08%, at the open to 34,109.88. The S&P 500 opened lower by 2.96 points, or 0.07%, at 4,170.46, while the Nasdaq Composite gained 2.35 points, or 0.02%, to 13,952.57 at the opening bell. (Reporting by Shivani Kumaresan in Bengaluru)