International Airlines Group saw traffic measured in revenue passenger kilometres increase by 12.2 per cent in December 2011 when compared to the previous year.
Growth was led by British Airways, which accounted for nearly 70 per cent of passengers flown, while Spanish counterpart Iberia saw virtually static demand.
Capacity at IAG measured in available seat kilometres was up 11.5 per cent over the period.
Premium traffic at the group for the month grew by 13.6 per cent compared to the previous year, with 12.0 per cent growth in non-premium traffic.
Overall figures were positively impacted by the non-recurrence of poor weather in December last year.
This particularly affected British Airways.
In December, Iberia pilots’ union went on strike for two days, with the Spanish flag-carrier able to operate 68 and 64 per cent of its flights on December 18th and 29th respectively.
In other developments, IAG and Lufthansa recently reached a binding agreement for IAG to acquire bmi for £172.5 million in cash.
In the UK, rising Air Passenger Duty (APD) has led British Airways to reduce its recruitment levels in 2012.
It will now only create 400 extra jobs rather than the 800 previously planned.
Iberia has begun to recruit pilots for its new subsidiary Iberia Express with more than 1,600 applying so far.