Asian shares on Wednesday struggled at two-year lows after Chinese stocks extended their fall, stoking fears about the stability of China’s economy. Japan’s Nikkei (.N225) fell 0.5 percent and South Korea’s Kospi (.KS11) lost 1.3 percent. MSCI’s broadest index of Asia-Pacific shares outside Japan slid to a two-year low and was last down 0.1 percent.