Rolls-Royce could axe up to 8,000 jobs after aircraft manufacturers were forced to cut production during the Covid-19 pandemic.
The aeroplane engine maker employs 52,000 people worldwide, with 23,000 staff in the UK.
According to a company source, senior leaders have warned "cuts could be as high as 8,000, but efforts to mitigate the impact are ongoing".
It had announced plans to save £750m but now "needs to take further action".
Rolls-Royce is expected to tell staff the actual number of job losses by the end of May.
The aviation industry has been badly hit by the pandemic as many flights across the world have been suspended.
The impact has forced aircraft manufacturers to cut production - Airbus has cut its production by a third and has furloughed 3,200 staff.
Rolls-Royce, one of the world's largest makers of aircraft engines, had previously warned the virus was a "macro-risk for everyone".
The Financial Times first reported the potential job losses, and said the restructuring plan "would shrink the workforce...by up to 15%".
Derby council leader Chris Poulter said it was "worrying" after Rolls-Royce confirmed some of the 10,000 staff at its two sites in the city could be affected.
As well as Derby, the firm has operations in six other UK locations. It also has a presence in the US, Germany, India, Singapore and Japan.
A Rolls-Royce spokesman said the pandemic was "unprecedented", adding: "We have taken swift action to increase our liquidity, dramatically reduce our spending in 2020, and strengthen our resilience in these exceptionally challenging times.
"But we will need to take further action. We have promised to give our people further details of the impact of the current situation on the size of our workforce before the end of this month."
It added negotiations were ongoing and it would "consult with everyone affected".
The Unite union said it was "making no comment whatsoever at this stage".