Ryanair's Chief Executive Michael O'Leary has criticised as a "stitch-up" the way that Air Berlin was carved up after it filed for insolvency, with Lufthansa buying the bulk of its operations and easyJet getting some business at Tegel.

An investment by Ryanair at Tegel "would allow Berlin's residents and visitors to avoid higher fares expected from a duopoly of Lufthansa and easyJet," Chief Commercial Officer David O'Brien said in Friday's statement.

Unlike Lufthansa's deal, easyJet's purchase of some Air Berlin business has so far not raised notable competition concerns in Germany or by the European Commission.

"EasyJet looks forward to providing passengers with low fares to a wide range of destinations to and from Tegel," a spokeswoman for the British carrier said in response to Ryanair's statement.

Ryanair said the slots at Tegel would allow it to make up for around 30 percent of capacity lost when Air Berlin ceased operations in October. The carrier already has nine aircraft at Berlin's other airport, Schoenefeld.

(Reporting by Maria Sheahan; Additional reporting by Alistair Smout; Editing by Andrea Shalal and Elaine Hardcastle)

Stocks treated in this article : Deutsche Lufthansa, Air Berlin Plc, Ryanair Holdings plc, EasyJet