BAA, majority owned by Spanish infrastructure group Ferrovial, reported an adjusted pretax loss of £116.9m in the six months to the end of June, down from a loss of £167.4m in the same period a year ago.
BAA, the owner of London Heathrow - Europe's busiest airport, said revenues grew 12.1 per cent to £1.07bn and that passenger traffic rose 7.1 per cent to 41.1m.
"Year on year performance was influenced by external factors in 2010 including particularly disruption caused by volcanic ash and industrial action by British Airways cabin crew at Heathrow that together resulted in the loss of an estimated 2.2 million passengers," BAA's Chief Executive Colin Matthews said.
BAA, which owns Glasgow, Edinburgh and Aberdeen airports in Scotland, as well as Heathrow, Southampton and Stansted in England, said it expects annual profit to come in at around £1.12bn on revenues of roughly £2.3bn.
The company, which was last week told by Britain's Competition Commission (CC) that it must begin selling off London Stansted airport and one of its Scottish hubs, said it was still considering a judicial review of the decision.