British Airways has revealed a steep loss for the April-to-June quarter after being hit by cabin crew strikes and disruption caused by the volcanic ash cloud from Iceland. BA reported a pre-tax loss of £164m, larger than the £148m loss it made in the same period last year, BBC News informs.

BA said the impact of all the disruptions was £250m in the quarter, in line with previous estimates. But it said total costs for the quarter were down 3.3% on a year ago. Revenues at the airline were down 2.3%.

BA also said that the UK pensions regulator had approved its plan to reduce its pension deficit, which is central to BA's merger with Iberia.

The Spanish carrier now has until 30 September to review the plan. If it deems it unsatisfactory, it has the right to pull out of the merger. The ash cloud from the Icelandic volcano caused airlines a headache in April, with UK airspace closed for six days as a result.

But the greatest impact on BA was caused by industrial action taken by staff.

BA cabin crew who are members of the Unite union have gone on strike for a total of 22 days so far this year, including 15 in the reported quarter.

The BBC's employment correspondent Martin Shankleman said the 15 days of strikes in May and June had cost the airline £142m. That was on top of the losses incurred for the seven days of strikes in March, which BA had previously said cost between £6m and £7m a day.

That puts the overall costs of the strikes so far at between £184m and £191m.