Shares in Japan's Olympus surged by more than 20 percent in Tokyo trade on Thursday, one day after its under-pressure chairman and president resigned over a fee payments scandal. The company had earlier held a press conference defending payments made in a series of deals at the centre of the scandal, which had wiped out around half of its share value and prompted two leadership changes in less than two weeks. Olympus shares were up 21.92 percent at 1,340 yen in afternoon trade.