Nikkei up 0.8 pct, Chugai Pharm jumps on earnings

(Updates to midsession)

TOKYO, Oct 24 (Reuters) - Japan's Nikkei average rose 0.8 percent on Wednesday following gains on Wall Street, with Chugai Pharmaceutical Co Ltd (4519.T: Quote, Profile, Research, Stock Buzz) posting the biggest one-day percentage gain in almost two years on strong results.

The benchmark Nikkei .N225 ended the morning session up 128.01 points at 16,578.59. The broader TOPIX index was up 1 percent at 1,586.47.