Europe's biggest phone company Deutsche Telekom AG reported Thursday a 35-per-cent slump in second-quarter earnings as the strong euro and loss of German customers hit group profits, DPA reported. Germany-based Telekom said it booked net profits of 394 million euros (608 million dollars) in the latest quarter compared to 604 million euros. This followed a 2.9-per-cent drop in second-quarter revenue to 15.13 billion euros, with a tough round of savings helping to offset the pressure on the group's earnings. "We made good progress during the first half of the year in achieving our strategic objectives, both in operations and in cost savings," said Telekom chief Rene Obermann. But while fierce competition in Telekom's domestic German market led again to a fall in its fixed-line customers, the rise in the euro undercut revenue from the group's US operations, including its mobile phone business, T-Mobile USA, which has been a key driving force behind group profits. Revenue from T-Mobile USA slipped by 0.8 per cent during the first half also amid growing competition in the US mobile phone market.