Spain's telecoms regulator said on Tuesday it was studying fining Vodafone up to 2 million euros ($2.6 million) for failing to adhere to European roaming tariffs.
The CMT said in a resolution published on its website that Vodafone (Alcobendas, Spain) automatically gave customers travelling in Europe a 4 euro per day roaming tariff under one of its packages instead of Europe-approved tariffs that establish different maximum fees.
The European rules establish a ceiling of charges per minute for calls, for example.
The CMT said Vodafone must immediately stop automatically giving new customers the roaming plan.
Vodafone declined to comment. Company sources said its rates were better than the European tariffs and it would give customers until May 17 to decide whether they wanted to continue with the 4 euro deal.
($1 = 0.7659 euros)
(Reporting by Clare Kane; Editing by Helen Massy-Beresford)