A European Court decision could cause headaches for the Vodafone Group/Liberty Global joint venture in the Netherlands.

The European Court of Justice overturned approval given in 2014 to combine two cable companies – UPC and Ziggo. The resulting company subsequently merged with Vodafone Netherlands to create an integrated fixed and mobile player, jointly owned by Vodafone and Liberty.

The issue revolved around the impact of the alliance on the pay TV market, with the review following a challenge by Dutch incumbent KPN.

A Financial Times report said this could cause “havoc” for Vodafone Ziggo, which will now need to seek merger clearance again, at a point when it is itself looking to integrate its fixed and mobile operations.

According to a statement made to the paper by Liberty Global, the court’s ruling “does not question the substance” of a European Commission “decision to approve the UPC and Ziggo merger, but rather annuls it on procedural grounds”.

The Vodafone/Ziggo deal was subject to separate approvals, which included the sale of some assets.

“We will discuss practical steps with the European Commission over the coming weeks and we are confident of obtaining clearance in due course,” the Liberty Global statement continued.