Peng Zhao replaces Kevin Turner atop Citadel Securities

NEW YORK (Reuters) - Kevin Turner has departed Ken Griffin's Citadel LLC less than a year after he joined as chief executive officer of the firm's market-making division, a spokesman said on Friday.

Longtime firm executive Peng Zhao was named to replace Turner as CEO of Citadel Securities LLC. Zhao joined Citadel in 2006 and rose to global head of market-making at Citadel Securities. In mid-2016 he became vice chairman and chief scientist of the overall firm.

Turner joined Chicago-based Citadel in July after more than a decade at Microsoft Corp. At the time, Griffin cited Turner's experience in building and managing large, complex businesses as a reason to bring him on board.

The reason for Turner's departure was unclear.

In statements on Friday, Griffin and Turner thanked one another.

Jamil Nazarali remains head of execution services and Paul Hamill remains global head of fixed income, currencies and commodities at Citadel Securities.

Citadel executed approximately 35 percent of all U.S.-listed shares traded on behalf of retail investors as of the first quarter of 2016, according to its website.

Citadel Securities reached a $22.6 million settlement with the U.S. Securities and Exchange Commission earlier this month related to charges that it misled customers about the way it priced trades. The activity at issue took place between 2007 and 2010, before Turner joined the firm.

(Reporting by Lawrence Delevingne and John McCrank; Editing by Lauren Tara LaCapra and Leslie Adler)