Buckley, who has been with the broadcaster for more than seven years, leaves at the end of this year. No decision has yet been taken over replacing him.
Buckley reports into London-based TBS Europe president Nan Richards and is the news counterpart to TBS entertainment networks managing director Lynne Frank.
Credited with the development of the CNN news operation, Buckley handles all distribution issues and new business developments of TBS' European networks including Cartoon Network, Boomerang, Turner Classic Movies and web activities.
Buckley said: 'For some time I have been considering taking a career break with a view to, amongst other things, furthering my studies at business school. I intend to use the next nine months to pursue some personal goals. I will then either look for a new challenge within Turner Broadcasting or elsewhere.'