TOKYO, Feb. 21 (Xinhua) -- Tokyo stocks advanced Wednesday morning as a comparatively weak yen versus the U.S. dollar prompted buying which accelerated away from selling in early trade on the back of soft U.S. shares overnight.

The 225-issue Nikkei Stock Average gained 139.45 points, or 0.64 percent, from Tuesday to 22,064.55.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, added 5.48 points, or 0.31 percent, to 1,767.93.

Glass, electric machinery and machinery-linked issues comprised those that gained the most by the morning break.