BERLIN (Reuters) - Budget airline Eurowings is interested in cooperating with other carriers on bookings with connecting flights, much like rivals Ryanair and easyJet have done, its chief commercial officer said on Thursday.

Ryanair said this week that it could provide connections with long-haul airlines in the future after signing a deal with Aer Lingus (>> International Consolidated Airlines Group), while Britain's easyJet last year signed a connecting flights agreement with Norwegian Air Shuttle.

Such deals are also of interest for Lufthansa-owned (>> Lufthansa Group) Eurowings because they could bring extra passengers to fill its planes, Oliver Wagner said at the ITB travel fair in Berlin.

"We're looking at it very closely, it's a topic for the future," he said, adding that Eurowings would be interested in working with providers of both short and long-haul flights.

Wagner cited the example of Kiwi, a site that searches for one-way tickets from various airlines and combines them to provide passengers on a budget with more choice of routes, instead of relying on only one carrier or on airlines that already work as part of an alliance.

Low-cost carriers typically provide only point-to-point services because of the extra costs involved in dealing with missed connections or lost baggage.

Eurowings is growing more quickly than expected as it competes with rivals to fill the gap left by the collapse of Air Berlin last year, and Wagner said a target to bring unit costs down to 5.8 euro cents by 2020 was not put at risk by the airline's rapid expansion.

"In fact, we are helped by the expansion because of scale effects. We can spread our fixed costs across a larger operation," Wagner said.

Eurowings is introducing a business class with a lie-flat bed on some of its long-haul flights from Duesseldorf next month in an effort to boost profitability.

"It's a logical step in a market like Duesseldorf, with a lot of purchasing power," Wagner said. "We know from our customers and corporate customers that the need is there for a lie-flat business class."

(Reporting by Victoria Bryan; Editing by David Goodman)