(Updates with U.S. services sector data)

NEW YORK, Sept 4 (Reuters) - The dollar extended gains versus the euro on Thursday after a report showed the U.S. services sector expanded slightly more than expected in August.

The euro EUR= was last down 0.4 percent at $1.4428, near session lows, compared with $1.4460 before the report.

The Institute for Supply Management said its non-manufacturing index came in at 50.6 for August from July's 49.5. A reading above 50 signals expansion. Economists expected an unchanged result of 49.5. (Editing by James Dalgleish)