U.S. bank JPMorgan Chase (JPM.N) has been placed under formal investigation in France as part of a probe into alleged tax evasion by senior managers at investment firm Wendel (MWDP.PA), a court official said on Wednesday. A Paris-based spokesman for JPMorgan declined to comment on the move, part of a wider investigation in which as many as 14 Wendel executives face charges including tax evasion and insider trading over transactions conducted in 2004-2007.