International Airlines Group has pointed to the high cost of fuel as the primary reason for widening financial losses.

The group – which controls British Airways, Iberia and bmi – lost €263 million over the first three months of 2012, compared to just €47 million for the same period of 2011.

However, revenue at IAG rose eight per cent to €3.9 billion, while group net debt was also down €19 million in the quarter to €1,129 million.

Fuel costs for the quarter were up 24.9 per cent to €1,409 million, with fuel unit costs up 24.0 per cent.

Of the losses, Spanish flag-carrier Iberia made an operating loss of €170 million in the quarter, while British Airway’s losses totaled €62 million.

IAG chief executive Willie Walsh explained: “Iberia’s performance reflects the weakness of the Spanish domestic market and industrial action by pilots opposed to actions by Iberia’s management to improve the airline’s efficiencies.

“For British Airways, although the London market and demand for transatlantic travel remains strong, its performance has been affected by rising fuel costs.”

Strikes at Iberia cost €25 million, as pilots continue to protest against the establishment of low-cost offshoot Iberia Express.

The airline said the outlook for the aviation industry remained uncertain.

Walsh also singled out government interference for its negative impact on the aviation industry.

“The financial performance of our business continues to be undermined by government actions,” he added.

“In addition to the UK government increasing the world’s highest aviation tax - Air Passenger Duty - by double the inflation rate, the Spanish government plans to increase departure taxes from Spain by up to ten euros per passenger.