The net loss was 2.12 billion euros ($2.24 billion), compared with a EUR946 million ($997.9 million) profit a year earlier, mainly due to a EUR2.2 billion impairment on its stake in the U.K.'s BT Group.
The declining share price of BT Group and a weaker exchange rate of the British pound against the euro following Brexit are the main reasons for the impairment, the German telecommunications company said.
Other special effects, including an impairment related to the Dutch business, also affected the result.
Revenues, however, rose 9.4% to EUR19.54 billion, helped by strong growth at majority-owned T-Mobile US Inc (TMUS). Adjusted earnings before interest, tax, depreciation and amortization of almost EUR5.27 billion were slightly below analysts' average estimate of EUR5.32 billion.
Deutsche Telekom proposed to raise the dividend to EUR0.60 a share after it paid EUR0.55 for 2015, in light of an improvement in full-year free cash-flow.
For the current year, Deutsche Telekom predicted revenue growth and adjusted Ebitda would rise almost 4% to around EUR22.2 billion.
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