Airline association Iata reported “a pick-up” in the financial performance of airlines in “every region except Europe” in the first quarter of the year.

However, Iata’s latest Airlines Financial Monitor noted a near 5% fall in airline share prices worldwide in April, with the sector underperforming the wider equity market by the widest margin in almost a year.

It noted US airline shares had fallen by 12% on average since the start of the year.

The decline in investor confidence follows the rise in oil prices with Brent crude costing about 50% more than a year ago and prices in April at a near four-year high.

The US government rejection of the Iranian nuclear deal this week pushed oil prices even higher, with Brent crude reaching $77 a barrel.

Iata also attributed the pressure on share prices to investor concerns at rising capacity.

However, it noted: “Every region with the exception of Europe registered a modest annual improvement in profit margin.”

The association reported the number of available seats in the world’s airline fleet was up 5.5% in March on a year earlier.

Iata-member airlines took delivery of 172 new aircraft in March, up from 145 in the same month a year ago. An additional 166 aircraft returned to the global fleet from storage during the month, with 123 removed.