April 8 (Reuters) - The benchmark S&P 500 hit a record high on Thursday, helped by gains in tech-related stocks, a day after the Federal Reserve reiterated its pledge to keep interest rates low until the economic recovery is more secure. The Dow Jones Industrial Average rose 23.6 points, or 0.07%, at the open to 33,469.89. The S&P 500 rose 10.0 points, or 0.25%, at the open to 4,089.95, while the Nasdaq Composite rose 108.0 points, or 0.79%, to 13,796.892 at the opening bell. (Reporting by Shivani Kumaresan in Bengaluru; Editing by Arun Koyyur)