Bristow helicopters
Sixty-six pilots' jobs are under threat, says Balpa
Bristow Helicopters could make 130 of its 1,950 UK staff redundant.
The Aberdeen-based company said it was continuing to be hit by a downturn in the North Sea oil and gas industry.
It said it had taken measures to cut costs but had not been able to meet levels needed and 130 employees may now be made redundant.
Pilots union Balpa has called for a summit to be held urgently on jobs security and said it would be fighting to save the threatened posts.
Balpa said up to 66 pilots face losing their jobs.
Consultation between Bristow and unions has started.
The company said it had set out "difficult yet necessary" proposals to help it compete in a highly competitive market.
'Devastating news'
A spokesman said: "The company has taken numerous measures to reduce costs by working closely with clients to improve operational efficiencies, eliminate discretionary spending, defer capital spend, and offer voluntary redundancy.
"However, we have not been able to reach the level of cost reduction needed and approximately 130 personnel may be affected by redundancy in the UK.
"Bristow is fully committed to ensuring the highest levels of safety standards are maintained throughout this difficult process."
Balpa general secretary Jim McAuslan said: "This is devastating news for the Bristow community and Balpa is doing everything it can to support pilots who are affected.
"This announcement reflects the collapse in the oil price and its impact on North Sea industry.
"Pilots want to see that industry thrive again and ensure when it does, we have the skilled pilots and other workers available."
He added: "Balpa will do all it can to protect pilots who are feeling the brunt of the downturn in the North Sea oil industry."
Scottish Labour's energy spokesperson Lewis Macdonald said the announcement by Bristow was an indication of the "severe problems" still facing the oil and gas industry in Scotland.
He added: "It is essential that those who are facing redundancy receive support from government at every level, and that the skills base in the oil support sector in the north east is protected."
'Package of support'
A UK government spokesman said: "The UK's oil and gas industry supports hundreds of thousands of jobs, and we want to make sure it's in the best possible position to manage the current decline in the oil price.
"We can't control the price of oil - but we've delivered on the Wood Review recommendations and established the Oil and Gas Authority.
"In addition, the package of support announced in the March Budget is expected to encourage over £4bn of additional investment in the UK's oil and gas industry over the next five years."
A Scottish government spokesman said: "The Scottish government has already held large-scale jobs events for the offshore industry in Aberdeen, attracting more than 1,700 people who received advice and practical support, job opportunities, start up support, further education and up-skilling opportunities. All individuals attending these events have been offered one-to-one follow up.
"We set up the energy jobs taskforce in January, which is helping protect jobs by coordinating action between government, the wider public sector, industry, unions and industry bodies.
"This is making a positive difference at a challenging time. The taskforce is driving forward a detailed action plan that aims to support offshore operators and the supply chain."