Spain's antitrust body said it fined telecoms companies Telefonica, Vodafone and France Telecom's Orange a record 120 million euros ($159 million) for charging too much for text messages.
The regulator said on Thursday Spain's three biggest mobile operators had exploited their dominant position between 2000 and 2009 and passed on overpriced services termination rates to consumers with high charges for text messages.
Former monopoly Telefonica (Madrid, Spain) must pay 46.5 million euros, while Vodafone (Newbury, UK) and Orange (Paris, France) must pay out 43.5 million euros and 30 million euros respectively, the National Competition Commission(CNC) said in a statement.
Revenue from text messages has dropped significantly in Spain to 184 million euros in the second quarter of 2012 from 419 million euros in the fourth quarter of 2008, according to Spain's telecoms watchdog CMT.
Telefonica charged 0.15 euros a message in Spain until 2006, when it halved the price in exchange for a fee of 2 euros a month.
The average cost of MMS messages in Spain rose to 0.64 euros per message in 2009 from 0.38 euros in 2005, while termination rates remained stable, according to the CNC.
Operators have faced rising competition from free instant messaging services such as WhatsApp and cheap offers from smaller players like Yoigo and virtual mobile operators.
"Telefonica totally disagrees with the fine imposed by the CNC today because it considers it completely unfair," a Telefonica source said, adding that the company would appeal.
Vodafone, which has the second highest market share in Spain and no.3 player Orange, also said they would appeal the CNC's decision.
(Reporting by Robert Hetz and Jesus Aguado; Writing by Clare Kane; Editing by Paul Day and Mike Nesbit)