NPR's President and CEO Gary E. Knell is stepping down after less than two years on the job, the organization's board announced Monday.
Knell, who took the post in December 2011, will become the President and CEO of the National Geographic Society sometime this fall. His replacement has not been announced.
"NPR is and will always be a beacon of journalistic integrity, commitment and courage," Knell wrote in a letter to employees. "Thank you for giving me the opportunity to work with you."
In National Geographic Society's announcement of his appointment, Knell said: "I am deeply honored to have been chosen to lead this incredible organization as it celebrates 125 years of educating people through its media about the world in which we live."
NPR media reporter David Folkenflik tweeted that the announcement came as a surprise: "Staffers at NPR react with widespread astonishment at news of Knell's departure. He leaves at end of first two-year contract in November."
Knell takes over from John Fahey, who will continue on as chairman of the board, the National Geographic Society said.