Prosecutors demanded a 10-year prison term Monday for Yasuo Hamanaka, a former Sumitomo Corp. trader, for inflicting losses of about $770 million on his firm through illicit copper trading.
Hamanaka, 49, has been charged with fraud and forging documents. The defendant has admitted to most of the charges brought against him, and the Tokyo District Court is expected to end hearings in the case after the final argument by the defense Feb. 25.
In their statement, prosecutors said Hamanaka betrayed Sumitomo regarding the coverup of his illicit trading for over 10 years. They went on to say that Hamanaka could be described as a "specialist in criminal copper dealing."
While inflicting unprecedented large losses on his employer, he reaped about 330 million yen in illicit gains through unlawful trading, they said. According to the prosecution, Hamanaka began repeated off-the-book trading to cover up losses he sustained together with his former superior around the summer of 1985.
He ran up losses totaling some $2.6 billion on unauthorized copper transactions on the London Metal Exchange during a 10-year period from 1985, according to the indictment.