"We are seeing a slowdown in the telecoms area. Orders are not being cancelled, but buyers are being cautious," he revealed.
"Perhaps a year ago, when telecoms companies needed to buy 100 units, they bought 110 because the extra might be useful, but now when they want 100, they try asking for 85 in the hope that would do the job."
Manhartsberger claimed telecoms companies were more unstable in Europe than in the US, largely due to the 3G licences. "They've invested $1bn (£666.7m) in licences in the UK and Germany and it will take another $1bn to get the infrastructure in place. For this reason, the German regulator has decided it is probably OK for competitors to co-operate on infrastructure," he said.
"It is difficult to see how they will make it work - it's a challenge for all providers."