AER Lingus carried just over 11 million passengers in December if its regional figures are included, a 3.2pc increase on last year.
The higher overall figures were driven by strength in its long-haul business.
However, short haul figures were lower.
"The reduction in December 2014 short haul capacity relates to planned network adjustments to protect margins given seasonal demand conditions," the company said in a statement today.
British Airways' owner IAG, which is headed up by former Aer Lingus boss Willie Walsh, is bidding to take over Aer Lingus.
However, Aer Lingus has so far rejected bids.
There has been speculation that IAG may now have indicated to Aer Lingus that it's prepared to pay between €2.40 and €2.60 a share for the Irish airline.
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