Staff at Canberra's major energy supplier are concerned their pay could be cut by up to $30,000 a year, according to their union.
The Professionals Australia union says some workers may be forced to apply for jobs well below their existing pay grade as ActewAGL goes through a process which has affected 135 staff.
Of these jobs, 14 will be made redundant.
David Smith, ACT director of Professionals Australia, which represents engineers at the organisation, said people's positions should not be downgraded.
He was unsure how many would find there were no jobs available at their existing pay rate and said the redundancy program would cause the loss of important skills for a significant price tag.
"They're not inexpensive redundancies. It would probably cost millions to pay them out," Mr Smith said.
ActewAGL acting chief executive Ayesha Razzaq confirmed some staff may receive less or more pay.
The organisation's new staffing structure and its newly created jobs were announced last week and she said there were 90 employees re-applying who could make use of a redeployment pool.
The other 45 had been appointed to positions.
"We understand that the changes are potentially very difficult for staff and the coming weeks will be challenging as we progress through the recruitment process," Ms Razzaq said.
"For those impacted by the changes, we have also provided both resilience training and job application training.
"We continue to provide a significant amount of additional support for impacted employees through our employee assistance program and confidential counselling and coaching."
The 14 redundancies equate to 1.5 per cent of ActewAGL’s workforce of 900 employees.
Ms Razzaq said no person in an existing job which was remaining would be re-classified to a different pay grade.
"The impacted employees will be applying for newly created roles," she said.
"This process is due to be finalised at the end of June 2014."
ActewAGL chief executive Michael Costello said in April a major redesign of the enterprise’s electricity business prompted the restructure.
"This is happening because our industry is changing at a rapid pace and we need to face this change head on so we can continue to deliver the cheapest and most reliable electricity supply in the country," he said.