(CNN) -- Barcelona and Real Madrid have been fined for breaking Spain's anti-competition laws when agreeing a television deal for their domestic league and cup soccer matches.
The two clubs, along with Sevilla and Racing Santander, must pay almost €8.5 million ($11.5 million) between them, while TV production company Mediapro has been fined €6.5 million ($8.8 million).
They were found guilty by Spain's National Markets and Competition Commission (CNMC) of agreeing a TV rights deal of longer than the stipulated three years.
In 2010, the clubs agreed four-year contracts with Mediapro.
Real was fined €3.9 million ($5.28 million), Sevilla €900,000 ($1.21 million) and Santander €30,000 ($40,624) -- all in line with the values of their respective contracts.
La Liga champion Barca said Monday it intends to appeal its €3.6 million ($4.87 million) fine within the allowed two-month window, but would pay despite it having "an economic impact" on this season's operations "subject to a favorable ruling on future courts involving the refund of payment made."
"FC Barcelona's appeal is based on the consideration that the signing of the contract was consistent with the provisions of the General Law on Audiovisual Communication, and also that the contract of assignment of rights mentioned has not affected in practice the audiovisual market," its website reported.
"The contract was signed by the previous Board, dated June 9, 2010, four days before the presidential elections. That decision was challenged by some candidates."
Sandro Rosell, Barca's current club president, took over from Joan Laporta -- whose reign lasted from 2003-10.
Spanish clubs, unlike those in other top European leagues, do not have collective television agreements.
Real and Barca hold 50% of the top division's TV income, with the other half shared among the other 18 clubs.
It has helped the leading duo not only dominate the domestic competition, but also become two of the world's most wealthy clubs -- allowing Real to splash out $132 million on Gareth Bale in August while also tying star player Cristiano Ronaldo to a lucrative new long-term contract worth a reported $206 million.
Barca's financial resources are not quite so deep, though have improved since accepting shirt sponsorship for the first time in 2010 with the Qatar Foundation -- a five-year deal reportedly worth up to $225 million. The club signed Brazil star Neymar for $75 million in May.
The CNMC said in a statement explaining the ruling that the four clubs and Mediapro had committed "a very serious offense" by breaking its April 14, 2010 ruling on the acquisition of broadcasting rights for football competitions.