The highest court in France on Wednesday rejected a bid by George Soros, the billionaire investor, to overturn a conviction for insider trading in a case dating back nearly 20 years, leaving the first blemish on his five-decade investing career. The panel, the Cour de Cassation, upheld the conviction of Soros, 75, an American citizen, for buying and selling Société Générale shares in 1988 after receiving information about a planned corporate raid on the bank. Ron Soffer, his lawyer, said Soros planned to take the case to the European Court of Human Rights, saying that the length of the proceedings...