The Federal Network Agency which regulates communications facilities, said it was reducing the amount T-Mobile, Vodafone, E-Plus and Telefonica/O2 could charge for calls between them, from a top price of €3.39 per minute to a maximum of €1.85 per minute. In a year's time this would be further reduced to €1.79 per minute, a spokesman said.
Jochen Homann, president of the agency, said the spread of smartphones and the accompanying rise in data transmission meant that voice transmission was accounting for a dwindling share of the total cost of mobile phone networks.
Telekom said the decision was difficult to comprehend, and that it would lose €500 million in turnover as a direct result, and this would be bad for future investments.
A Vodafone spokesman said the decision was completely the wrong signal, and would take money from the market which was needed for the expansion of digital infrastructure.
A four-week consultation period now starts, while the European Commission and EU regulatory bodies must also have time to comment.