Gasum in May took Gazprom to arbitration after the Russian group had demanded that Gasum paid in roubles for gas after Europe imposed sanctions on Moscow over Russia's invasion of Ukraine. Gazprom shortly after stopped natural gas flows to Finland.

"According to the award, Gasum is not obligated to pay in roubles nor through the proposed payment procedure," Gasum said in a statement on Wednesday.

Gasum, which has a long-term natural gas supply contract with Gazprom, said the arbitral tribunal also mandated the two companies to continue negotiations over the dispute.

Gazprom was not immediately available for comment when contacted by Reuters.

(Reporting by Essi Lehto, editing by Anna Ringstrom)