The proposal is part of Ryanair's attempt to persuade the European Commission that its planned 694 million euro (£596.7 million) takeover of Aer Lingus will not harm competition for Irish passengers.
Airline Flybe has boosted Ryanair's hopes of a takeover of Aer Lingus by agreeing a plan to fly 43 of the Irish carrier's short-haul routes.
Under the agreement, Flybe will receive a minimum of nine Airbus A320 aircraft and a cash injection of 100 million euro (£85.9 million) from Ryanair.
The newly created Flybe Ireland will operate from bases in Dublin and Cork, with many of the 34 European destinations served by the 43 routes already used by Flybe's UK business.
Ryanair will give Flybe the right to use the Aer Lingus brand for three years and will develop a business plan that should provide 20 million euro (£17.2 million) in pre-tax profits in the 12 months following the transfer.
The deal comes a month before the European Commission is due to give a decision on Ryanair's bid for Aer Lingus. Should the budget carrier succeed with its takeover, Flybe Ireland is expected to commence operations in time for the winter season.
Flybe chairman and chief executive Jim French said: "Flybe would be proud to have the chance to serve the Irish markets, and would be, as we seek to be throughout the rest of Europe, a good employer and corporate citizen.
"However, before Flybe Ireland can come into being there are many hurdles to overcome, not least the EC accepting the remedies offered by Ryanair in its offer to take over Aer Lingus, and then the shareholders of Aer Lingus accepting an offer from Ryanair."
Exeter-based Flybe, which flies from airports including Bristol, Cardiff, Doncaster, Edinburgh and East Midlands, recently announced plans to slash costs by £35 million as it looks to stem recent losses. It has been hit by the high cost of fuel and the impact of air passenger duty hikes.