Oct 9 (Reuters) - Wall Street's main indexes posted

subdued gains at open on Thursday after Federal Reserve Chair

Jerome Powell offered no fresh policy signals, leaving investors

to rely on older data to shape sentiment.

The Dow Jones Industrial Average rose 20.5 points, or

0.04%, to 46,622.31 at the open. The S&P 500 rose 6.8

points, or 0.10%, to 6,760.5​, while the Nasdaq Composite

rose 2.0 points, or 0.01%, to 23,045.329.