OSCOW, April 27 - The biggest shareholders of the oil giant Yukos on Tuesday nominated Viktor V. Gerashchenko, a former central banker who began his tenure in the Soviet era, as the chairman of the board. Yukos did not announce any other nominations to its board. The board will vote on nominees on Wednesday, and they will be presented at a general shareholders meeting for approval in June. "Yukos shareholders invited me onto the board of directors and I accepted," Interfax news agency quoted Mr. Gerashchenko as saying. Mr. Gerashchenko is a deputy in Parliament representing Rodina, a nationalist bloc...