July 2 (Reuters) - Major U.S. stock indexes opened about half a percent lower on Monday, starting the second half of 2018 on a grim note due to mounting worries of a tariff war between the United States and its trading partners.
The Dow Jones Industrial Average fell 109.88 points, or 0.45 percent, at the open to 24,161.53. The S&P 500 opened lower by 13.42 points, or 0.49 percent, at 2,704.95. The Nasdaq Composite dropped 58.41 points, or 0.78 percent, to 7,451.90 at the opening bell. (Reporting by Sruthi Shankar in Bengaluru; Editing by Arun Koyyur)