Kiev, Sep 19 : Kiev will file a lawsuit to the World Trade Organisation against Poland, Hungary and Slovakia over their decisions to extend a ban on grain imports from Ukraine, a senior official said. "It is important to prove that these actions are legally wrong. And that's why we will start legal proceedings," said Taras Kachka, Ukraine's trade representative and deputy minister of economy, the Interfax-Ukraine news agency reported. The unilateral bans by Poland, Hungary and Slovakia on Ukrainian grain after the decision of the European Commission to lift the restrictions have caused a major "systemic concern," Xinhua news agency reported quoting Kachka. The European Commission said that it has decided not to extend the embargo on Ukrainian agricultural products to five European Union member states, which expired on September 15. Despite the Commission's decision, Poland, Hungary and Slovakia refused to drop the ban, according to media reports. /IANS