British Airways has estimated that this summer's Gate Gourmet dispute cost it between £35m ($62m) and £45m.
BA saw its Heathrow flights grounded for two days in August
The airline saw its Heathrow flights grounded for two days in August after ground staff walked out in sympathy with sacked workers at its caterer.
Releasing its results for the three months to 30 September, BA saw its pre-tax profit fall 18% to £241m.
The drop came about because last year's figure was boosted by the sale of shares in Australian carrier Qantas.
"[The Gate Gourmet dispute] does not have a material impact on the quarterly financial comparisons as the airline also suffered operational disruption in the same period of last year," BA said in its statement.
In a BBC interview, BA's chief executive Willie Walsh described the second quarter figures as a "reasonable result in the circumstances".
Yet investors - which had been expecting strong results - seemed relatively disappointed, and BA's shares closed down 7.75 pence, or 2.4%, at 306p.
Pre-tax profits for the second quarter were down from £293m for the same period in 2004 when the Qantas sale brought in £86m.
The airline's second quarter turnover was up 8.2% to £2.2bn, from £2bn a year earlier.
Mr Walsh added that the airline still needed to do more to reduce its costs.
"It is clear, however, that we need to re-energise our drive on controllable costs," he said.
"We have demonstrated time and again that it is possible to offer world-class service while improving unit costs.
"Costs are up in most areas. Fuel was the biggest single contributor, up a staggering 51.3%.
"We must ensure a successful move to Heathrow Terminal 5 in 2008 and redouble our efforts to make British Airways more focused and better able to serve all of our customers."