PARIS — A widespread strike all but grounded the German flag carrier Lufthansa on Monday, affecting around 150,000 passengers around the world amid a battle over wages as the airline pushes ahead with a $2 billion restructuring program.

The airline, Europe’s largest by passengers carried, said it had to cancel all but 32 of its 1,700 scheduled flights worldwide after unions representing more than 33,000 ground crew and other staff, half its German work force, called the action. The full-day “warning strike” at Germany’s biggest airports — including Frankfurt, Munich and Hamburg — was the second such action in a month by members of the country’s powerful services union, ver.di. The union is seeking a 5.2 percent wage increase, job guarantees and a shorter, 12-month contract period.

The contract talks come as Lufthansa, like other large network carriers across Europe, struggles to keep a lid on operating costs. In the European market, Lufthansa and its peers are losing market share to leaner and nimbler rivals like Ryanair, easyJet and Air Berlin. On long-distance routes, they are being squeezed by rapidly expanding Middle Eastern carriers like Emirates and Etihad.

Lufthansa said it had managed to operate a small number of long-distance flights Monday, most of them to U.S. destinations. At Frankfurt, where Lufthansa is based, only 6 of 50 scheduled intercontinental flights took off: to Kennedy International Airport in New York, as well as Philadelphia and Atlanta in the United States; Madras, India; Nagoya, Japan; and Kuwait City. From Munich, only three trans-Atlantic flights — to Charlotte, North Carolina; Chicago and Miami — departed out of 17 scheduled. All three daily flights to the United States from Düsseldorf — to Newark Liberty International Airport, Chicago and Miami — operated as scheduled.