Beleaguered budget carrier Norwegian Air saw revenue click up as it carried more than 3.5 million passengers in August.

The peak summer month saw revenue rise by 3% year-on-year with a load factor edging up by 0.4% to 90%.

Total traffic increased by 5% with capacity growth of 4%.

But the carrier’s on-time performance was impacted negatively due to general summer delays in European airspace.

The use of leased aircraft due to late deliveries of grounded Boeing 737 Max aircraft in also hit Norwegian’s on-time performance. Just 76.2% of flights departed on schedule.

The August figures came just days after the airline disclosed that it was putting Gatwick take off and landing slots worth more than $380 million as security for an extension of financing packages ahead of the traditionally weaker winter flying season.

The airline’s acting CEO Geir Karlsen said: “Our growth is slowing down, in line with our strategy, and we are glad to see an increased unit revenue this month compared to the same month last year.

“We are also pleased that bookings are looking solid going forward, especially on intercontinental routes and in the Nordics.”

Continued fleet renewal contributed to a further reduction of CO2 emissions in August from 70 to 69 grams per passenger kilometre compared to the same period last year.

The airline said it had reduced its per passenger emissions by 30% since 2008.