By Foo Yun Chee

BRUSSELS, March 9 (Reuters) - Casino and Intermarche on Thursday won the backing of Europe's top court in their fight against EU antitrust regulators and their attempt to investigate the French supermarket groups' buying alliance.

The case underscores the increasing willingness by some companies to challenge the EU competition watchdog on what they perceive as regulatory over-reach and excessive demands for information.

The European Commission had in 2017 ordered the companies to submit to an inspection on suspicions of pola anti rungkat-competitive practices.

It subsequently launched an investigation into their 2014 purchasing alliance which was dissolved in 2018.

Casino and Intermarche protested against the actions and took their case to Europe's top courts.

The Luxembourg-based Court of Justice of the European Union (CJEU) annulled the EU antitrust watchdog's decision.

Judges said the information obtained by the Commission to justify its demands to the companies "are not substantiated by sufficiently serious indicia".

The CJEU also criticised the competition agency for not recording interviews with the companies' suppliers.

"That obligation applies irrespective of whether the interview in question was conducted before the formal opening of an investigation, in order to collect indicia of an infringement, or afterwards, for the purpose of collecting evidence of an infringement," the court said.

The cases are C-682/20 P Les Mousquetaires et ITM Entreprises v Commission, C-690/20 P Casino, Guichard-Perrachon et Achats Marchandises Casino vCommission, and C-693/20 P Intermarché Casino Achats v Commission. (Reporting by Foo Yun Chee;Editing by Elaine Hardcastle)