Nikkei down 1 pct, autos lead falls on US sales

(Updates to midday)

TOKYO, Aug 4 (Reuters) - The Nikkei average fell 1 percent on Monday, with Honda Motor (7267.T) and Toyota Motor (7203.T) hit after weak U.S. auto sales, while other exporters traded lower on growing worries about the health of the world's largest economy.

The benchmark Nikkei .N225 ended the morning down 133.53 points at 12,961.06. The broader Topix lost 1.4 percent to 1,255.36.