Financial services, construction and utilities reported the biggest falls in confidence, the BBC reported on Tuesday citing the Manpower Employment Outlook Survey.
The survey was conducted in the weeks after the referendum was held on June 23 to exit the European Union (EU).
Although UK job prospects have held firm, the survery said that "cracks in the ice were appearing".
The survey asked about 2,100 UK employers whether they plan to hire more workers, or cut jobs, in the last three months of this year.
Mark Cahill, ManpowerGroup UK managing director, said Britain was entering a new phase of prolonged economic uncertainty following the referendum on EU membership.
"Many finance operations in the City of London depend on the EU 'banking passport' and the fall in hiring intentions could reflect pessimism over the future of this agreement," the BBC quoted Cahill as saying.
There had been an 800 per cent rise in applications for finance jobs in Dublin since the Brexit vote, the survey said.
Hiring confidence among employers in the public sector, which accounts for almost one in 10 UK jobs, has sunk to its weakest level in more than four years, according to the research.
