Three senior staff members have been suspended from a social housing group that manages more than 8,400 council homes in North East Lincolnshire.
New management will run Shoreline Housing Partnership's property services while an investigation is carried out into its performance in the past year.
The group took control of the council's housing stock in March 2005.
It refused to comment on the reason for the suspensions but said it was in the best interests of its tenants.
The Shoreline Housing Partnership launched a £156m investment programme over 10 years when it took over the council's housing in 2005.
North East Lincolnshire Council said it was confident tenants would not be adversely affected by the changes.
"North East Lincolnshire Council is confident that the Shoreline Housing Partnership is delivering to the promises it made when the housing stock was transferred to it," a spokesman said.
"Tenants should be reassured that the council continues to monitor Shoreline's delivery against the transfer agreement, and an annual report is due to go before the council's scrutiny committee in June."