Called Working, Fitzpatrick said the agency will focus on internal communications, initially in partnership with freelance experts.
Fitzpatrick joined Marconi two years ago from Bell Pottinger as its first global internal communications head during a period of massive upheaval for the firm.
Marconi was forced to axe thousands of jobs and sell off parts of the company to tackle massive debts following an acquisition spree during the short-lived telecoms boom.
A source at Marconi said that following Fitzpatrick’s decision to quit, internal communications has been restructured and his role axed.
Instead executive vice-president of resourcing and development Elisa Nardi, has taken on internal communications as part of her role. She takes the title executive vice president of internal communications, resourcing and development.
The Marconi source added: ‘When Liam joined it was a much bigger firm. We went through a radical restructure and there was a need to focus on the internal communications.
‘Now its very much business as usual and we can spend more time looking at the training and development of staff.’
Nardi, as with Fitzpatrick, reports to director of communications David Beck.