AER Lingus is to consult with unions on changing staff contracts to reflect the "seasonality" of their business, the Irish airline has said.
In its 2013 results yesterday, it said revenue had grown 2.3% from €1.39bn (£1.15bn) in 2012 to €1.425bn (£1.18bn) in 2013, though pre-tax profit fell 2.2% from €40.4m (£33m) to €39.5m (£32.6m).
The airline, which flies to Spain, Portugal and London Heathrow from Belfast City, has said it will introduce a 'cost optimisation' programme.
Spokesman Declan Kearney said that would not entail saving money by cutting routes.
Instead it would change its "business processes" to make up for the fact that the airline's activity peaked in the summer months.
"Demand fluctuates massively throughout the seasons so we are looking at changing business processes... it's early days but we have no plans to cut routes or frequency or curtail capacity in any way. It's more about productivity."
Mr Kearney said last year's hot summer had meant that people on both sides of the border opted to stay at home instead of booking last-minute breaks.
He said 2013 had been a "challenging" year with the second half more challenging than the first.
The third quarter had seen the hot weather result in a dearth of late-in bookings, while the final quarter saw "aggressive pricing" from Ryanair on short-haul flights driving down profits.
He said he saw George Best Belfast City Airport as working with Dublin Airport, which has carried out a campaign to entice Northern Ireland travellers to fly long-haul from it.
"We have a twin track strategy in relation to the Northern Ireland market. We have no long-haul flights out of Northern Ireland and we see Dublin for long-haul flights as effectively the long haul airport for the island."
He said research had shown that the optimum location for long-haul airports was anywhere within two hours driving time, and most parts of Northern Ireland were so placed.