Irish airline Aer Lingus Group Plc pledged to make a small profit this year and next year as it set out its defence against the €750 million takeover bid from Ryanair Holdings Plc.

Aer Lingus, already nearly 30 per cent owned by its low-cost rival, said in a statement that the offer significantly undervalued the group and said it could succeed as an independent carrier.

"Despite ... extremely challenging conditions, we expect to achieve profit overall this year," chairman Colm Barrington said in an open letter to shareholders, adding that cost cuts and lower fuel prices had boosted the group's prospects.

Director of Corporate Affairs Enda Corneille later said this year's profit would be small and would not include the cost of restructuring the airline's workforce in the autumn.

"We will make a small pre-tax profit this year and pre-exceptional costs, with the same again next year," he said, without giving the exact cost of the restructuring.

Ryanair replied in a statement that it was misleading to forecast a profit when after tax and exceptional items the carrier would in fact make a loss.

"The reality is that Aer Lingus has incurred substantial - as yet undisclosed - exceptional costs, and companies have to pay tax, so the result will be another year of substantial net losses," chief executive officer Michael O'Leary said in a statement.

Ryanair has bid €1.40 a share in cash for the portion of Aer Lingus it does not already own and wrote to shareholders directly last week.

The offer values the rump shares at €525 million and the entire airline at €750 million - about half what it offered in an earlier takeover attempt two years ago.

That bid was blocked by the European Commission for being anti-competitive and Mr Barrington said he saw no reason why regulators would think any differently this time around.