Ground and cabin staff at German airline Deutsche Lufthansa will strike on Monday in a dispute over pay, threatening travel chaos at the height of the holiday season.

The Verdi union said more than 90 percent of workers supported an open-ended walkout to back demands for a 9.8 percent pay hike.

Flag carrier Lufthansa, Europe's second biggest airline by passenger numbers, has offered 6.7 percent in two stages and a one-off payment.

The strike will hit maintenance and repairs along with catering, which is likely to at least delay intercontinental flights.

Earlier this week, Lufthansa cancelled almost 1,000 regional flights at its Eurowings and CityLine subsidiaries after pilots walked out in a separate pay dispute.

At 1217 GMT, Lufthansa shares were down 2.43 percent, underperforming the wider DAX index which had slipped 0.99 percent.

At a time when Europe's biggest economy is seeing a spike in inflation, several labour unions are seeking bigger wage deals after restraint in recent years.

Pay increases already agreed this year include a 5.2 percent rise for steelworkers and 4.4 percent for employees in the chemicals industry, some of the largest increases since the mid-1990s. Inflation in June was 3.3 percent. "From Monday we will be taking industrial action," Erhard Ott, head of Verdi, told a news conference.

The strike is due to start at 2200 GMT on Sunday and could hit travellers in cities such as Frankfurt, Berlin, Hamburg and Munich, among others.

Lufthansa, which like other airlines is under pressure to keep down costs due to soaring fuel prices, said it could not estimate the impact of the strike.