 JMP Group LLC NYSE: JMP, an investment banking and alternative asset management firm, today announced management changes, including the resignation of Carter Mack from his position as president of the company and the promotion of Mark Lehmann to the role of chief executive officer of JMP Securities, the companys primary operating subsidiary. Additionally, Thomas Wright has been named chief operating officer of JMP Securities, while managing directors Jonathan Dever and Gavin Slader have been named co-heads of investment banking and have joined JMP Groups executive committee. 