The firm said the cuts were due to ‘declining workload’ and ‘efficiencies necessary in the current economic climate’.
However, there is no change in the amount Kier is being is paid by Sheffield Council for its contract to repair council houses.
All 1,050 workers at Kier Sheffield, a subsidiary of the national building and property firm, were sent a letter warning them of the job losses.
A Kier spokeswoman said: “As a result of the current economic downturn, Kier Sheffield is in consultation with trade union representatives regarding a reduction in staff numbers by approximately 50.
“We will do everything we can to help those affected secure work elsewhere in the business wherever possible. We do not expect this to impact on our service delivery.”