The overseeing of offenders in Bristol, Somerset, Gloucestershire and Wiltshire was “among the worst in the country”, a probation report found.
The HM Inspectorate of Probation inspection also found some officers had “dangerously high workloads”.
Seetec took over from Working Links, which went into liquidation in February. The inspection took place shortly after the takeover.
The new service provider said it was making “big strides” in improvement.
Inspectors looked at the quality of work with people under probation supervision before the takeover and rated the planning, implementation and review of those cases analysed as “inadequate” and among the worst work they had seen anywhere in the country.
But the watchdog said the service, called Bristol, Gloucestershire, Somerset and Wiltshire (BGSW) Community Rehabilitation Company (CRC) was making progress under the new management and gave it an overall rating of “requires improvement”.
Its work to support people leaving prison was rated “good”.
‘Pursuing right actions’
Justin Russell, chief inspector of probation from HM Inspectorate of Probation, said before the takeover “staff did not always pay sufficient attention to managing risks and keeping other people safe”.
He added: “Urgent action is needed to ensure staff understand the importance of public protection work. Managers need to ensure staff are suitably trained to deliver this work and there is appropriate oversight.”
Mr Russell also said the new owners were “pursuing the right actions” and had started to invest in staff and infrastructure.
Dawn Blower, chief officer of the region’s probation service, said: “We’ve made big strides already in terms of improving the service here, we’ve been actively recruiting staff.
“There’s an additional 20% additional funding to the area, we’ve started to re-train staff in our probation practice.”
The service manages about 6,300 offenders who are classed as medium or low risk.
Prisoners are supported just before they are released and for a year afterwards. It also supervises all community orders.
The inspectorate report said that almost half the criminals re-offended and potential risks to members of the public were not explored by probation officers.
The government has admitted the privatised system of probation is not working and by the end of 2020, it will be re-nationalised.