July 26 (Reuters) - U.S. stock indexes fell from record highs on Monday as locally listed Chinese firms tumbled on tighter regulations in the mainland, marking a poor start to a week packed with technology earnings and a Federal Reserve meeting. The Dow Jones Industrial Average fell 5.69 points, or 0.02%, at the open to 35,055.86. The S&P 500 opened lower by 2.21 points, or 0.05%, at 4,409.58, while the Nasdaq Composite dropped 15.96 points, or 0.11%, to 14,821.03 at the opening bell. (Reporting by Sagarika Jaisinghani in Bengaluru; Editing by Aditya Soni) Our Standards: The Thomson Reuters Trust Principles.