Sept 18 (Reuters) - Wall Street's main indexes opened

slightly higher on Wednesday, as the Federal Reserve was widely

expected to deliver its first interest rate cut in more than

four years, with most investors betting on a 50-basis point

reduction.

The Dow Jones Industrial Average rose 22.7 points, or

0.05%, at the open to 41,628.91. The S&P 500 rose 7.1

points, or 0.13%, at the open to 5,641.68​, while the Nasdaq

Composite rose 35.3 points, or 0.20%, to 17,663.383 at

the opening bell.