"We are extremely satisfied with the bookings," Jens Bischof, chief commercial officer of Lufthansa German airlines, said on the sidelines of the FVW travel conference.

"The marketing campaign only started last week and when we consider that most of these bookings were done without marketing, then it's good news for us," he added.

Lufthansa will start flights with premium economy seating, which offers more leg room, luggage allowance and entertainment options, in a couple of weeks' time.

Customers can book the class for long-haul flights departing in December and beyond, but during the first weeks of operation, customers will be offered free upgrades from economy.

Lufthansa has said premium economy will make up around 10 percent of seat capacity on its long-haul flights, carrying around 1.5 million passengers a year in the class.

(Reporting by Victoria Bryan; Editing by David Holmes)