Bmibaby is set to be closed by British Airways in September with some flights being cut from next month.
BA’s parent firm IAG, which acquired Bmibaby as part of the Bmi purchase from Lufthansa, said it had started a consultation period with the no-frills airline's 470 staff to “review future options for the Bmibaby business”.
A series of routes, including all flights from Belfast, are to finish from June 11 while all flights will end from September 10 – for full details click here.
“We will continue to operate Bmibaby flights to the majority of our summer destinations from East Midlands and Birmingham airports until Sunday, September 9, 2012,” said Bmibaby in a statement on its website.
“We recognise this news may be frustrating for customers and we would like to apologise for any inconvenience caused. We will do all we can to keep you up-to-date with the latest information and make the process as smooth as possible.”
IAG had been looking to sell Bmibaby but chief executive Willie Walsh last week said he was “not confident” that a buyer could be found.
Bmi’s interim managing director Peter Simpson said: "Bmibaby has delivered high levels of operational performance and customer service, but has continued to struggle financially, losing more than £100 million in the last four years. In the consultation process, we will need to be realistic about our options.
“To help stem losses as quickly as possible and as a preliminary measure, we will be making reductions to Bmibaby's flying programme from June. We sincerely apologise to all customers affected and will be providing full refunds and doing all we can with other airlines to mitigate the impact of these changes.”
The move to shut down Bmibaby came a day after Flybe decided to launch five new routes from East Midlands airport for the winter. Leisure airlilne Monarch is also setting up a base at East Midlands and expanding services from Bmibaby's other key hub Birmingham.
Jim McAuslan, general secretary of pilots union BALPA, called the move "bad news for jobs" and vowed to everything it could to help its members.
"Bmibaby pilots are disappointed and frustrated that, even though there appears to be potential buyers, we are prevented from speaking with them to explore how we can contribute to developing a successful business plan," said McAuslan.
"The frustration has now turned to anger following the news that other airlines have moved on to these Bmibaby routes without any opportunity for existing staff to look at options and alternatives."
IAG added that "progress has been made with a potential buyer for Bmi Regional" - the Aberdeen-based subsidiary which is also facing an uncertain future unless it can be sold.