July 2 (Reuters) - Wall Street's main indexes opened

lower on Tuesday as megacap stocks retreated after a strong

session, with additional caution creeping in ahead of jobs

opening data and comments from Federal Reserve Chairman Jerome

Powell later in the day.

The Dow Jones Industrial Average fell 61.27 points,

or 0.16%, at the open to 39,108.25. The S&P 500 opened

lower by 13.25 points, or 0.24%, at 5,461.84, while the Nasdaq

Composite dropped 71.26 points, or 0.40%, to 17,808.04

at the opening bell.