Jobs would be created rather than lost at Aer Lingus after a takeover by Ryanair, the budget giant claims in its detailed offer document for the Irish flag carrier.

The no-frills airline said its plan to raise annual passenger numbers at Aer Lingus from 9.5 million to 14 million would require hiring more pilots, cabin crew and engineers.

It aims to achieve that growth by reducing ticket prices, while maintaining margins by boosting “the productivity of [Aer Lingus] staff” to reduce unit costs.

The airlines would operate separately under one holding company, according to the plans, with Ryanair continuing to serve budget customers on point-to-point flights, next to Aer Lingus’s “high frequency, mid-frills short haul services to primary airports and its transatlantic operations”.

The offer is Ryanair’s third attempt in six years to buy its national rival.

Rejecting the Ryanair offer, Aer Lingus said today it is a “robust and profitable airline with a proven business model, a strong balance sheet and an internationally recognised brand”.

A statement said: “Aer Lingus’ strategy of building a leaner and more efficient business is working.

“Operational and financial performance has improved greatly since 2009, resulting in a turnaround in operating result since that time of approximately €130 million. We have transformed a loss making Aer Lingus into a profitable airline with one of the strongest balance sheets in the European sector.”

Aer Lingus said the reasons for the European Commission blocking Ryanair’s 2006 offer on competition grounds are now “even stronger than before” as the number of routes that Ryanair would monopolise has sharply increased.

“Your board has received legal advice that the European Commission is likely once more to prohibit the Ryanair offer, and that this is not therefore a credible offer which is capable of completion,” Aer Lingus said.