Ukrainian businessman Dmytro Firtash has won two court victories in a bitter divorce dispute involving his ownership rights over his multibillion-dollar business empire, which includes a key supplier of natural gas to Ukraine and the European Union, according to the Financial Times.

But his ex-wife, Maria Firtash, pledged to pursue lawsuits in other courts in a bid to gain 50 per cent ownership in businesses she claims to have played a major role in establishing.

In a statement on Wednesday, Mr Firtash’s holding company, Group DF, announced that Kiev’s Pechersky District Court had on July 19 rejected Ms Firtash’s plea to cancel divorce settlement agreements signed in 2005-2006. Group DF also revealed the High Court of the British Virgin Islands ruled on a separate matter against Ms Firtash who had applied for the disclosure of confidential records of companies controlled by Mr Firtash.

The dispute has come as 45-year-old Mr Firtash, who is trying to boost the transparency of his businesses, has created a newly-consolidated holding company called Group DF. Group DF’s portfolio includes interests in Ukrainian television, property, chemicals and Mr Firtash’s his prime asset - a 45 per cent stake in Swiss-registered gas trader RosUkrEnergo, a gas trading company he owns jointly with Russia’s Gazprom.

In a Financial Times interview last month, Ms Firtash said she would seek a 50 per cent interest in these businesses, or equal compensation, through litigation. Ms Firtash, who is 51, was in her mid-30s when she met Mr Firtash in the early 1990s. She said the couple worked together in what was originally her business.

Speaking to the Financial Times on Wednesday, Ms Firtash downplayed the importance of the two court rulings in her overall dispute. She pledged to pursue other lawsuits in and outside of Ukraine.

”I have sued and will continue to sue. I have all the appropriate documents to defend my case,” Ms Firtash said.