U.S. video game sales fall 8 pct in September - NPD

* Software sales fall 6 pct, hardware off 19 pct

* Xbox shows growth; "Halo: Reach" is top game

SAN FRANCISCO Oct 14 (Reuters) - Sales of video game software and equipment fell 8 percent in September, industry tracker NPD said on Thursday, as digital content continued to eat into traditional gaming revenue.

Software sales dropped 6 percent to $614 to million, while hardware sales tumbled 19 percent to $383 million.

Sales of accessories rose 13 percent to $180 million, helped by the release of Sony Corp's (6758.T) new Move controller for the PlayStation 3.

Microsoft Corp's (MSFT.O) Xbox 360 was the only game console to post year-over-year growth in September, boosted by the launch of "Halo: Reach," which is only available on the Xbox.

"Halo" was the best selling game in the month, at 3.3 million units, not including those bundled with hardware.

"While industry sales of new physical retail sales show a decline versus a year ago, it's important to remember that there is a growing volume of content being sold digitally, or otherwise, outside the traditional retail channel," NPD analyst Anita Frazier said in a statement.

NPD's monthly data does not cover used games, digital sales, or other online and wireless channels, which are growing quickly.

Many gamers pay for content through downloads, or by going online to play social games such as those offered by Zynga. Apple Inc's (AAPL.O) iPhone has also turned into a major gaming platform, with users purchasing games through the App Store. (Reporting by Gabriel Madway; Editing by Richard Chang)