U.S. stocks opened modestly higher on Thursday, after the European Central Bank left interest rates unchanged and provided clarity on the timeline for its bond-buying program. The Dow Jones Industrial Average rose 0.3% to 25,282. The S&P 500 added 0.3% to 2,783. The Nasdaq Composite Index was up 0.4% to 7,726. The ECB laid out plans to taper its program of monthly bond purchases later this year, aiming to bring them to a halt by the end of 2018. Separately, a read on retail sales was up 0.8% in May, stronger than expected, while jobless claims fell by 4,000 in the latest week. In company news, 21st Century Fox Inc. climbed 1.2% a day after Comcast Corp. offered to buy a big chunk of Fox’s entertainment and international assets for $65 billion. On Wednesday, stocks ended at their lows of the session after the Federal Reserve signaled a slightly more aggressive plan to tighten monetary policy this year than had previously been projected.