(Sharecast News) - Wizz Air reported a 3.9% year-on-year increase in passenger numbers for September on Wednesday, carrying 5.76 million passengers during the month.

The FTSE 250 low-cost carrier said that despite engine-related groundings of its more efficient Airbus A321neo fleet due to issues with Pratt & Whitney GTF engines, it managed to increase seat capacity by 4.8%, though load factors dipped slightly to 91.7%, down from 92.4% in September last year.

For the second quarter, Wizz Air saw seat capacity rise by 1.2% year-on-year to 19.11 million, while passenger numbers grew by 1.1% to 17.90 million.

The company also highlighted its ongoing expansion, as it announced new routes in the month for its Airbus A321XLR aircraft, which would operate daily services between London Gatwick and Jeddah, and Milan Malpensa and Abu Dhabi, starting next summer.

However, the airline recorded an increase in carbon emissions per passenger kilometre.

Emissions per revenue passenger kilometre rose 2.5% year-on-year to 52.3 grams, a result of the less efficient fleet mix following the grounding of newer aircraft.

At 0803 BST, shares in Wizz Air Holdings were down 1,24% at 1,350.02p.

Reporting by Josh White for Sharecast.com.