Aug 27 (Reuters) - Wall Street’s main indexes extended gains on Friday as Federal Reserve Chair Jerome Powell signaled the U.S. central bank will remain patient as it tries to nurse the economy back to full employment. In prepared remarks for a speech to the Jackson Hole economic conference, Powell said the U.S. economy continued to make progress towards the central bank’s benchmarks for reducing its pandemic-era emergency programs, but stopped short of signaling the timing for any policy shift. At 10:04 a.m. ET, the Dow Jones Industrial Average was up 172.86 points, or 0.49%, at 35,385.98, the S&P 500 was up 24.65 points, or 0.55%, at 4,494.65, and the Nasdaq Composite was up 88.54 points, or 0.59%, at 15,034.35. (Reporting by Sagarika Jaisinghani in Bengaluru; Editing by Saumyadeb Chakrabarty) Our Standards: The Thomson Reuters Trust Principles.