Ryuichi Koike, the "sokaiya" corporate extortionist at the center of a huge financial scandal, pleaded guilty Tuesday to taking about 12.4 billion yen in illicit payoffs from the Big Four brokerages and Dai-Ichi Kangyo Bank.

Koike, 54, admitted accepting 370 million yen from Nomura Securities Co., 202 million yen from Daiwa Securities Co., 14 million yen from Nikko Securities Co., 11.7 billion yen from Dai-Ichi Kangyo and 107 million yen from Yamaichi Securities Co. The money was allegedly for favors and compensation for trading losses.

Koike is charged with violating the Commercial Code by accepting the payoffs and the Securities and Exchange Law by taking compensation from the four brokerages for trading losses. "I admit all the facts on each of the indictments," he said after prosecutors read the charges at his first session before the Tokyo District Court.