Air Berlin filed for insolvency this week after its main shareholder, Abu Dhabi's Etihad Airways, withdrew its financial support.
"The federal German government, Lufthansa and other partners are supporting Air Berlin in its restructuring efforts. The federal government is supporting Air Berlin with a bridging loan to maintain flight operations for the long-term," the Air Berlin said.
"Negotiations with Lufthansa and other partners regarding the acquisition of business units of Air Berlin are far advanced and highly promising," it said.
Ryanair, however described this as an attempt to "carve up Air Berlin’s assets, while excluding major competitors and ignoring both EU competition and state aid rules".
"Now even the German government is supporting this Lufthansa-led monopoly with €150 million of state aid so that Lufthansa can acquire Air Berlin and drive domestic air fares in Germany even higher than they already are. German customers / visitors will suffer higher air fares to pay for this Lufthansa monopoly," Ryanair said.
"Bearing in mind the scale of the market shares and the European implications involved, it is all the more important that the European Commission takes immediate and decisive action," it said.