By Joanna Plucinska

LONDON (Reuters) - Europe's major airlines including Lufthansa and Air France-KLM are expected to report another quarter dragged down by rising costs and limited planes, with no sign of delivery delays from planemakers Boeing and Airbus improving any time soon.

While demand has remained stable, costs for maintenance, adverse weather, air traffic control issues and disruption in the Middle East have continued to weigh on carriers.

Delays of new plane deliveries are the biggest ongoing headache, though, forcing airlines to fly older models that are more expensive to maintain and use more jet fuel and cut traffic estimates.

Lufthansa Chief Executive Carsten Spohr warned the airline is now expecting a five-year delay on its Boeing 777X deliveries.

"We don't expect to get them until 2026. And we need them," he told journalists earlier this month.

The German carrier is expected to report on Tuesday a third-quarter operating profit of 1.3 billion euros ($1.4 billion), down 9% from a year ago and a margin of 12.1%, according to a company-led analyst poll.

The airline is losing up to $550,000 per flight on its route from Frankfurt to Beijing as a result of flying older jets with few passengers, according to a Bloomberg report. Lufthansa did not immediately respond to a Reuters request for comment.

British Airways, owned by IAG, has said it will cancel more long-haul flights due to delivery delays from engine maker Rolls-Royce.

Air France-KLM is also set to take a hit on third-quarter revenue, according to analysts, due to lower ticket bookings tied to the Paris Olympics. It reports results on Nov. 7.

These challenges have dragged airline shares down in the last six months. And while they've recovered slightly in the last month, investor worries over the sector's health have prevailed.

Only IAG has seen a substantial hike in its share price, up over 20% in the last six months as it continues to build on its strength in the North Atlantic market and faces fewer delivery delays.

The airline is expected to report on Nov. 8 an operating profit of 1.78 billion euros, according to a company-led analyst consensus, up 2% from last year.

BLEAK OUTLOOK

Some airlines have said that the worst is yet to come. Delivery delays could hit harder in 2026 as current supply chain issues impact new plane production.

That said, with fewer available seats due to constrained capacity, airlines can charge higher fares if demand stays robust as it is expected to, analysts say.

But that dynamic does not seem to be playing out.