Deutsche Lufthansa AG cabin crews extended their strike into Saturday, disrupting the plans of an estimated 58,000 passengers flying from Frankfurt and Dusseldorf. Following a nine-hour walkout in both cities on Friday, the flight attendants began a 17-hour work stoppage at the two airports that led to the cancellation of 520 flights, company spokesman Boris Ogursky said by phone. Those on strike are responding to a call by the UFO union that’s disputing retirement changes for crews sought by Lufthansa to save money. With the union announcing its strike plans with little notice, Lufthansa scrambled to inform passengers of cancellations, Ogursky said. The company sent 27,000 short texts or e-mails to fliers, he said. “We’re prepared operatively,” said the Frankfurt-based spokesman. Lufthansa has sought to re-book flights with partner airlines, offer train tickets, waive cancellation fees and arrange hotel accommodation. Talks between Lufthansa and UFO broke down on Nov. 3. The union said on its website that the carrier is on track to have its most successful year ever. Stoppages will continue through Nov. 13, it said, while no strike is planned for Sunday. Munich will be unaffected by walkouts through the weekend because of local travelers returning at the end of school vacations in southern Germany. The strike could become the longest by Lufthansa’s cabin crews. The flight attendants’ previous large-scale walkout was a three-day protest in 2012 that cost the carrier 33 million euros ($35 million) after 1,500 flights were scrapped. That compares with the 352 million euros and 9,700 cancellations tied to a series of pilot strikes since last year. UFO has agreed to a switch of Lufthansa’s pension system to a defined-contribution program from defined benefits. The airline said this week that the union is seeking to maintain payments at previous levels, while Lufthansa wants employees to work additional years to reach that figure. Ogursky said Lufthansa’s only long-haul cancellation on Saturday is a Dusseldorf-Newark, New Jersey, flight. Almost all European flights from Frankfurt, the carrier’s biggest airport hub, will be dropped except a few to Munich and three serving London Heathrow. The strike doesn’t extend to Lufthansa’s CityLine, Germanwings, Eurowings, Air Dolomiti, Austrian Airlines, Swiss or Brussels Airlines divisions, said Ogursky. (By Brian Parkin/Bloomberg)