Chrystia Freeland, the Financial Times' US Managing Editor and TV regular, is leaving the newspaper for Thomson Reuters, where she will serve as global editor-at-large.
Freeland will be replaced by assistant editor Gillian Tett who oversees the newspaper's markets coverage.
"Chrystia has been a driving force behind the FT's success in the US for the past four years, and has contributed to the FT's global profile in many other senior roles in London and Moscow," editor Lionel Barber said in an announcement. "I wish her the very best with her future endeavors."
Barber also praised Tett for her "award-winning coverage of the global financial crisis."
"Having led the markets team from London, and with a wealth of global experience, she is ideally placed to lead the next phase of the FT's editorial development in the US," he said. "She will play an important ambassadorial role in the region and strengthen our growing influence in the North American market."