FRANKFURT (Reuters) - Any merger that Deutsche Telekom may enter into in the United States must deliver real value in terms of synergies, its finance chief said when asked why it was proving so difficult to strike a deal with Sprint or another party.


"It depends on how sure you can be to really get out the synergies you have on a piece of paper," Thomas Dannenfeldt told analysts on a call after Europe's biggest telecoms provider reported second-quarter earnings on Thursday.


Fourth-biggest U.S. wireless carrier Sprint said on Tuesday an announcement on merger talks should come in the "near future".


It has been exploring a merger with Deutsche Telekom's T-Mobile US as well as with cable provider Charter Communications.


Deutsche Telekom on Thursday repeatedly refused to comment on the current situation.


But Dannenfeldt said in-market consolidation did in general offer opportunities, and a mobile-to-mobile merger was the easiest way of creating synergies.

T-Mobile US has previously tried and failed to merge with U.S. network operators AT&T and Sprint. It merged with Texas-based MetroPCS in 2014.

Deutsche Telekom has wavered at times over the years about its commitment to remaining in the U.S. market. T-Mobile US is now its primary growth and profit driver.

(Reporting by Georgina Prodhan; Editing by Arno Schuetze)