Plans for a pan-European Irish airline to take on British Airways, Lufthansa and Air France were unveiled today as Ryanair relaunched its takeover bid for Aer Lingus.

The offer, valuing Aer Lingus at €748 million (£620 million), is pitched at €1.40 a share - exactly half the price Ryanair offered for the former state-owned Irish flag carrier two years ago during a bid in which it secured 29.8% of its rival.

That offer foundered on the opposition of the Irish government, which retains a 25% holding in Aer Lingus, and on European Commission opposition on competition grounds.

"Things have clearly changed over the last two years - the world of airlines is not what it was," said Ryanair chief executive Michael O'Leary. "Since we first bid for Aer Lingus, British Airways is doing its deal with Iberia, Lufthansa has taken over bmi British Midland, and we have already had the merger of Air France with KLM.

"Airlines have been collapsing all over the place. There is patently consolidation in the airlines market and we want to be part of it. Europe will have a Big Four - four big consolidated airline groups - and they will be Lufthansa, Air France, British Airways and Ryanair."

O'Leary has yet to open talks with the Irish government. He hopes to win over ministers with the lure of €190 million for its share in Aer Lingus to boost the cash-strapped Irish economy, and by the promise of 1000 new jobs by doubling the Aer Lingus short-haul fleet to 66.

"The Irish government backed Aer Lingus before, when Aer Lingus strategy was independence, growth and profitability," he said. "What we have instead is high fares, fuel surcharges and the promise of losses for 2008 and 2009."

Ryanair plans to run Aer Lingus as a separately branded, full-service, multi-class airline, which will also give it access to the transatlantic market.

The offer for Aer Lingus would also see a €137 million bonanza for its staff, who hold 18% of the airline through an employee share trust. Aer Lingus executives are likely to reject Ryanair's latest advances.

It is understood they will reject the offer on the grounds of Ryanair's opportunism over Aer Lingus's bombed-out share price, which was today at €1.12, half what it was at the start of the year.