Dec 17 (Reuters) - Warner Bros Discovery's board rejected Paramount Skydance's $108.4 billion hostile bid on Wednesday, saying it failed to provide adequate financing assurances. In a letter to shareholders, disclosed in a regulatory filing, the board wrote that Paramount had "consistently ​misled" Warner Bros shareholders that its$30-per-share cash offer was fully guaranteed, or "backstopped," by the Ellison family, led by billionaire ‌and Oracle co-founder Larry Ellison. "It does not, and never has," ...