Ryanair is suing the European Commission for not taking action against governments allegedly giving illegal aid to national carriers.

In the latest round of a bitter battle between Brussels and the Dublin-based airline, Ryanair said it submitted complaints involving Air France, Lufthansa, Alitalia and Olympic Airways to the Commission over a year ago.

In a statement, Ryanair said: "These complaints involved hundreds of millions of euro in illegal state aids being granted by the French, German, Italian and Greek governments to subsidise their flag carrier airlines.

"Although Ryanair has called on the Commission several times to investigate these claims, the Commission has failed to do so."

A fortnight ago the airline launched a court appeal against the Commission's decision to block Ryanair's takeover of Irish national carrier Aer Lingus.

A statement by the Commission blamed Ryanair's reputation for "aggressive retaliation" for restricting the chances of open competition between airlines.

Ryanair has accused European regulators of having a "twin track" approach and being "more concerned with protecting inefficient flag carrier airlines and hub airports than ... with actually promoting competition".

The airline said there were "blatant abuses" of state aid rules, including the discounting of domestic airport fees in France, losses on a new terminal for Munich Airport in Germany and cash injections into Alitalia and Olympic.