FRANKFURT (Reuters) - German airline Air Berlin’s insolvency administrator is suing Abu Dhabi’s Etihad, its former owner, for damages of up 2 billion euros ($2.26 billion), a Berlin court said on Friday.

Etihad Airways’ decision to withdraw funding for Air Berlin sent Germany’s then No.2 carrier into insolvency. The administrator said previously that Etihad did not meet its financial obligations towards Air Berlin.

“The claims are for payment of 500 million and the establishment that the defendant is obliged to pay further damages. The Chamber has provisionally set the amount in dispute at up to 2 billion euros,” the court said in a statement on Friday.

Etihad’s spokesperson confirmed the company had received a claim filed at the Berlin Regional Court by the insolvency administrator of Air Berlin.

“We believe that the claim is without merit and will defend ourselves vigorously against it,” the spokesperson said, adding that they would not make further public comment on the issue at the present time.

The airline has until the end of January to respond to the suit, according to the court.

Etihad owned a 29 percent stake in Air Berlin and had been providing funding since becoming a shareholder in early 2012. In April 2017, Etihad sent a letter of support to Air Berlin, saying it would continue to provide funding for the next 18 months.

But just months later, Etihad said it would no longer provide funding, saying Air Berlin’s business had deteriorated at an unprecedented pace.

The administrator said this doomed Air Berlin, whose assets have since been carved up and sold off.