More than a dozen workers at the Wrexham-based Dee Valley Water company face losing their jobs after its £84m takeover by Severn Trent.
The new owners have undertaken a review and feel there are “areas of duplication” and are, so far, unable to find alternative roles for 14 people.
Severn Trent are “in consultation” with workers over possible redundancies.
North Wales AMs Mark Isherwood and Llyr Gruffydd have highlighted fears about the future of the employees of Dee Valley, which has 230,000 customers across the Wrexham and Chester areas.
Before the takeover, First Minister Carwyn Jones had said he would “not support any change that would mean the loss of Welsh jobs”.
But Severn Trent have announced possible job losses, which are mainly “support roles”, two months since the High Court ruled they could take over Dee Valley Water.