Asset management firm Legg Mason has realigned its senior management responsibilities as it focuses on its future growth opportunities.

Legg Mason has named Joseph Sullivan as new head of global distribution. As the firm’s chief administrative officer, he led the firm’s streamlining initiatives. He will be responsible to enhance Legg Mason’s penetration on a global basis by adopting best practices from both the Americas and International distribution teams. He will also continue to oversee the execution of the transition plans established for the company’s recent streamlining initiative to its conclusion.

Ronald Dewhurst has been named head of global investment managers. As head of International for Legg Mason, he led the expansion of the firm’s international business. He will now work with Legg Mason’s investment affiliates worldwide on strategic initiatives to build their business, and will be based in New York.

Jeffrey Nattans has been named head of M&A and business development. He will lead the organization’s efforts on strategy, mergers & acquisitions and strategic affiliate initiatives. Since joining from Goldman Sachs in 2006, he has worked on strategy and growth initiatives for the firm and will also draw upon his recent experience in working with the firm’s specialized investment managers.

Peter Nachtwey has been named to an expanded CFO role. He will join the firm in January, after serving as CFO of The Carlyle Group, where he also held responsibility for many of the firm’s operational and technology functions. He spent more than 25 years at Deloitte & Touche. At Legg Mason, he will take on responsibility for many critical administrative areas within the Corporate Center.

Thomas Lemke, Legg Mason’s general counsel, will join the firm’s Executive Committee. He will have expanded responsibility that includes legal and compliance, the US Fund Boards, Global Fund Administration, Internal Audit and Risk Management.

All five executives report to Mark Fetting and together form the firm’s Executive Committee. David Odenath, formerly the head of the Americas for Legg Mason, will leave Legg Mason at year end to pursue other opportunities.