Hyundai Heavy Industries Holdings (HHIH) has criticised the European Union's "unreasonable" decision to prohibit its proposed merger with Daewoo Shipbuilding and Marine Engineering.

The shipbuilder is now preparing a possible legal appeal against the ruling, announced today by EU competition commissioner Margrethe Vestager.

"After reviewing the final decision of the [European] commission, HHIH will pursue possible measures, including an appeal to the General Court of the EU," HHIH said.