BAA, the UK airports operator, has had to take a £261m (€290m) hit in profits from its London division because of a ballooning pension deficit, as industry experts warn more companies may suffer the same fate despite improving financial conditions.

BAA, which reported nine month interim accounts for its London airports today, said it had to reflect a £261m pension deficit in its results which helped drag it to a £670m loss for the first nine months of the year.