* Toshiba ends 2.2 pct lower after news to pick govt-led Japan-U.S.-Korea group to buy chip unit
* Takata has dropped 50 pct over past 4 days
By Ayai Tomisawa
TOKYO, June 21 (Reuters) - Japan's Nikkei share average fell on Wednesday as a stronger yen sapped risk appetite, while mining stocks underperformed as oil prices tumbled.
The Nikkei fell 0.5 percent to 20,138.79 points, moving away from near two-year highs marked the previous day.
Wall Street stocks dropped overnight after energy shares lost ground, which also hurt sentiment in Asian trade.
The mining sector underperformed and fell 1.3 percent after oil prices fell about 2 percent on news of increases in supply by several key producers.
"A stronger yen combined with a fall in oil prices had made investors stay on the sidelines," said Hikaru Sato, a senior technical analyst at Daiwa Securities.
The dollar was down 0.2 percent at 111.220 yen, off a near one-month peak of 111.790 touched on Tuesday.
Inpex Corp stumbled 1.2 percent and Japan Petroleum Exploration Co dropped 1.9 percent.
Conversely, cheaper oil prices helped airline shares as fuel charges are a major cost component for operators. Japan Airlines rose 0.3 percent while ANA Holdings Inc gained 0.5 percent.
Banking stocks took a breather after being bought recently. Mitsubishi UFJ Financial Group dropped 1.3 percent and Sumitomo Mitsui Financial Group fell 0.7 percent.
After opening higher, Toshiba Corp ended 2.2 percent lower in volatile trade. Sources said the firm will pick a Japanese government-led group of Japanese, U.S. and South Korean firms and funds to buy its chip business.
Takata Corp remained untraded with a glut of sell orders and ended at its daily limit low of 244 yen at the market close. Sources said last Friday that the maker of defective air bag inflators is preparing to file for bankruptcy as early as this week. The stock has nosedived 50 percent in the past four days.
The broader Topix fell 0.4 percent to 1,611.56. (Editing by Kim Coghill)