Wizz Air lowered its annual profit forecast on Thursday after reporting a 44% drop in its first-quarter operating profit, below analyst expectations, partly owing to costs related to Pratt & Whitney's engine troubles and one-off wet leases to bolster capacity.

The low-cost airline, which flies an all-Airbus fleet, has faced challenges related to Pratt and Whitney RTX engines, with 46 of its planes set to be grounded for inspections this summer, placing constraints on its capacity.

European airlines generally have faced a difficult first half of the year because of spiralling costs and a normalisation in customer demand.

The budget carrier forecast net income for the year in the range of 350 million euros to 450 million euros ($379 million -$487 million), from an earlier forecast of 500 million euros to 600 million euros.

Wizz Air said demand remained strong and that it was still planning on substantial capacity growth in the coming years, with new Airbus planes boosting its fleet.

"We remain on track to return to annual capacity growth in 2026, underpinned by the pipeline of Airbus deliveries," Chief Executive Jozsef Varadi said in a statement.

Operating profit in the company's first quarter to June 30 was 44.6 million euros, against the 144.3 million euro consensus in an LSEG analyst poll.

($1 = 0.9239 euros)

(Reporting by Joanna Plucinska and Yadarisa Shabong in Bengaluru Editing by Savio D'Souza and David Goodman)