German carrier Air Berlin has filed for insolvency at the local district court of Berlin-Charlottenburg after its main shareholder Etihad Airways decided to withdraw its financial support.

The filing is expected to allow the airline to continue its restructuring process, which is currently underway.

Air Berlin is also receiving support from the federal government and its rival Lufthansa in its restructuring process.

The government has granted a €150m bridging loan to enable the carrier to continue its flight operations for up to three months, reported the BBC.

“We are working tirelessly to achieve the best possible outcome for the company, our customers and employees, given the situation.”

Air Berlin reported a record loss of €782m last year.

The airline is also in discussion with Lufthansa and other partners on the acquisition of its business units. The discussions are expected to end soon.

Air Berlin CEO Thomas Winkelmann said: “We are working tirelessly to achieve the best possible outcome for the company, our customers and employees, given the situation.”

In a separate development, Irish airline Ryanair has lodged complaints with German and EU competition authorities to prevent Lufthansa’s possible acquisition of Air Berlin.

It has been alleged that the insolvency of Air Berlin has been established will allow Lufthansa to take over the company debt-free.

If approved, it will breach all German and EU competition rules, alleges Ryanair.