NEW YORK (Reuters) -Blackwells Capital upped the pressure on Walt Disney in a long-running boardroom battle by suing the entertainment giant on Thursday for information that may point to possible disclosure violations in dealings with hedge fund ValueAct Capital. The suit, filed in a Delaware court, is the latest chapter in a fight over who will sit on Disney's board and help guide the home of Mickey Mouse in business and personnel decisions. Blackwells and another hedge fund, Trian Fund Management, are trying to persuade investors to elect their director candidates while Disney is backing its own directors.