Staff at Ceredigion County Council are facing "insecurity" in the wake of the recommendations of the Williams Commission.
The report, released last week, says that Ceredigion should merge with Pembrokeshire - and possibly with Carmarthenshire.
"The report has created insecurity for our workforce," chief executive Brownwen Morgan told this week's Cabinet meeting.
"All members of staff have had a letter explaining the situation. It's difficult to foresee the future and we need to analyse and study the report in detail."
She added that the report would be discussed at scrutiny and Cabinet level.
"It is too soon to discuss now but there will be an opportunity over time."
Decisions on the report's recommendations are due to be made by Easter.
Council leader Cllr Ellen ap Gwynn said: "I think Easter is a bit of a stretch as the recommendations are far reaching."
Meanwhile Preseli Pembrokeshire MP Stephen Crabb has said the Welsh Assembly should "tread carefully" with reorganisation.
“Ministers in Cardiff should tread carefully with any major re-organisation of Welsh local government, and particularly with respect to Pembrokeshire which benefits enormously from having its own council,” he said.
"Pembrokeshire is a historic County with its own distinct identity, geography and economy. Our food, tourism and hospitality businesses all benefit from the strength of the Pembrokeshire brand. The disappearance of Pembrokeshire County Council would undermine that."
“The Commission produced two options for Pembrokeshire - to merge with Ceredigion, or see a return to the old Dyfed authority. To describe either of these as ‘local’ authorities would be wrong. There is a real risk that the needs of Pembrokeshire could be sidelined in a larger council area. Indeed, the merger of the Pembrokeshire Health Board with Carmarthenshire and Ceredigion a few years ago, and the battle for Withybush as a result, provides a pointer as to the risks to local services that could follow the abolition of Pembrokeshire.”
“Local people fought hard over many years to get Pembrokeshire back from the old Dyfed authority and I do not want to see a step backwards.I will be raising my strong concerns with the Welsh Minister who will need to approach this issue with care.”