July 30 (Reuters) - Refiner Phillips 66 posted a

fall in quarterly profit on Tuesday, hurt by a slump in margins

due to a tepid summer driving season and a rise in global

refining capacity.

The Houston-based company reported a net income of $1.0

billion, or $2.38 per share, in the second quarter, compared

with $1.7 billion, or $3.72 per share, a year earlier.