(Updates with opening)

TOKYO, Oct 24 (Reuters) - The Nikkei average fell 0.8 percent on Friday, with high-tech exporters down after Sony Corp (6758.T: Quote, Profile, Research) halved its full-year profit forecast, while U.S. stocks ended mixed in volatile trade.

As of 0001 GMT, the Nikkei shed 69.94 points to 8,391.04, after falling 2.5 percent the previous day.

The broader Topix .TOPX slipped 0.8 percent to 864.60. (Reporting by Aiko Hayashi)