Mr. Mason was a portfolio manager for seven Nuveen high-yield funds. His duties will be assumed by Gunther Stein, CIO and portfolio manager of Symphony, and his investment team, Ms. Sujata said.
Ms. Sujata could not say whether Mr. Mason left the company for a new job or whether his position will be filled.
Mr. Stein and his staff will continue to manage the Nuveen Senior Income; Nuveen Floating Rate Income; Nuveen Floating Rate Income Opportunity; Nuveen Multi-Strategy Income and Growth; Nuveen Multi-Strategy Income and Growth 2; Nuveen Diversified Dividend and Income; and Nuveen Tax-Advantaged Total Return Strategy funds.
Nuveen had $119 billion in assets under management as of Dec. 31.