Passenger numbers jumped 7.3 per cent at Aer Lingus last year as an increase in people taking short-haul flights offset a decline in long-haul passengers.
However, load factors declined across all routes as the group added more flights and increased frequencies to existing destinations.
The figures were released yesterday as talks between unions and management to avert a possible strike continued at the Labour Relations Commission.
The unions are opposing changes to working practices scheduled to come into effect at the start of next month for new employees, claiming that the company is breaching an earlier agreement by implementing them without consultation.
If no agreement is reached, a strike could take place as early as the second week of February.
Aer Lingus carried 8.6 million passengers in 2006, up from eight million in 2005.
Short-haul routes accounted for 7.5 million of the passengers, with the remaining 1.1 million travelling to long-haul destinations such as New York, Boston and Dubai.
Load factors - a measure of how well the airline is filling its seats - were down on all routes compared with the previous year, with long-haul again leading the decline, down 5.8 percentage points at 80.3 per cent.
The load factor on short-haul routes slipped 1.5 percentage points, to 75.4 per cent, significantly below the 83 per cent reported by rival Ryanair in its latest set of traffic statistics for 2006. Ryanair carried 40.5 million passengers last year.
During the year Aer Lingus added 13 new routes, equal to a 21 per cent increase in capacity, a development the company said contributed to the overall decline in the load factor.
Long-haul, which chief executive Dermot Mannion has identified as a key revenue driver for the company in the years ahead, was also affected by the terrorist alerts in the UK during the summer and the removal of one plane from the Dublin to Orlando route in favour of a new route between Dublin and Dubai.
In December, Aer Lingus carried 634,000 passengers, an increase of 4.5 per cent over December 2005.
