The takeover of bmi by British Airways is set to lead to up to 1,200 job losses, the airline announced on Thursday.
BA started consulting unions on proposals to integrate the bmi business into its operations at Heathrow Airport after the acquisition was given regulatory approval from the European Commission last month.
BA said that without the acquisition, all 2,700 bmi jobs could have been lost.
The jobs facing the axe are at bmi's head office at Castle Donington in Derbyshire and at regional airports.
Jobs secured include 1,100 cabin crew, pilots and engineers at Heathrow and up to 400 passenger service roles at Heathrow's Terminal One.
Keith Williams, British Airways’ chief executive, said the deal was "good news for our customers", adding: “bmi is heavily loss making and is not a viable business as it stands today. Our proposals would secure around 1,500 jobs that would otherwise have been lost. As we look to restructure the business and restore profitability, job losses are deeply regrettable but inevitable. We will work with the unions to explore as many options as possible and are already working with industry partners."
The acquisition of bmi mainline will give BA an additional 56 average daily slots at Heathrow, of which up to 14 will be available to other carriers. Retained slots will be used to expand BA's operations at Heathrow with new destinations and more schedules.
Discussions with potential buyers for bmibaby and bmi Regional are continuing.
In a statement the company said: "The acquisition of bmi by British Airways’ owner, International Airlines Group (IAG), was given regulatory approval from the European Commission in late March. bmi is losing more than £3m a week and, without this acquisition, was facing closure with the potential loss of all 2,700 UK based jobs.
"The consultation proposes the full integration of bmi mainline into British Airways securing approximately 1,500 jobs. The integration proposals could result in up to 1,200 redundancies.
"Jobs secured under the proposals include the transfer to British Airways of around 1,100 cabin crew, pilots and engineers based at Heathrow."