Channel 4 News deputy editor Martin Fewell has announced he is leaving the programme a month after the departure of former editor Jim Gray.
Fewell joined ITN in 1998 as a programme editor on the 7pm bulletin and became deputy editor of Channel 4 News in 2002, working with Gray on last year's relaunch.
He started his career as a local radio trainee reporter in 1987 and was later deputy editor for The World at One & The World This Weekend. He was launch editor on BBC News 24 and has also worked for Newsnight and BBC One O'clock News.
'I'm immensely proud to have worked with such a strong and committed team at Channel 4 News and to have been deputy to a terrific editor like Jim Gra,'he said.
'I'm not sure I can top the experience as a journalist, but what I've learned from a brilliant, creative set of colleagues & friends at ITN will stay with me as I head off to find new opportunities.
'The programme is in great shape, in great hands and it feels like the right time to try something new."
On 10 July, Channel 4 News' head of foreign news Ben de Pear was named as the new editor of Channel 4 News, succeeding Gray, who stepped down two weeks after almost 14 years at the broadcaster.
De Pear joined Channel 4 News as a senior foreign producer in 2005 and had been head of foreign news for seven years.
Commenting on Fewell's departure, ITN's chief executive John Hardie said: 'Martin will be sorely missed by his colleagues here at ITN. He brings absolute professionalism, passion and an intellectual edge to every project he leads.
'He was instrumental in our review of the programme last year, and before that played a key role in developing Channel 4 News as a multimedia brand. We wish him all the best."
Channel 4 News said that recruitments for de Pear and Fewell's replacements will commence with immediate effect.
It also said de Pear is expected to make an announcement on a new senior team in the coming weeks.