Broadcasters spend billions of euros to buy exclusive rights to shows top flight sport such as England's Premier League and Spain's La Liga soccer to attract viewers.
The Commission said late on Tuesday it had carried out unannounced inspections in several member states at companies that distribute "media rights and related rights pertaining to various sports events and/or their broadcasting".
Fox Networks Group (FNG), an operating unit of Murdoch's 21st Century Fox which distributes TV and cable channels around the world, said it was cooperating with the inspection after officials raided its offices in London.
"The Commission has concerns that the companies involved may have violated EU antitrust rules that prohibit cartels and restrictive business practices," the Commission said in a statement.
Ziggo Sport, a Netherlands-based broadcaster owned by Liberty Global and Vodafone , said on Wednesday it was also involved.
"We have been informed that the European Commission is inspecting several media companies in Europe, including Ziggo Sport," it said.
"Ziggo Sport is cooperating fully with the European Commission's inspection and is unable to comment further at this stage."
The raid comes at a difficult time for Fox, which is engaged in string of deals that are facing regulatory approval, and for Ziggo's owners Vodafone and Liberty Global which could soon be in a similar position.
Fox is battling Comcast and British regulators for the right to buy Europe's biggest pay-TV company Sky for around $15 billion while it has also agreed to sell a string of assets to Walt Disney Co for around $52 billion.
Vodafone, meanwhile, is in talks to buy some of Liberty Global's cable networks in some other European countries where they both operate, chief of which is Germany.
(Reporting by Paul Sandle; Editing by Kate Holton and Keith Weir)
