When £54bn ($93.2bn) worth of bank loans was offered to Telefonica to fund its acquisition of O2 this month, it sent a chill of apprehension across Wall Street and the City of London.

The sum was triple the amount the Spanish telecoms group actually needed to seal its deal and is thought to be the most since 2000 when France Telecom received €100bn in loans to acquire Orange, a UK mobile phone group.