Bulgaria's biggest private gas supplier Overgas is challenging actions of Russian energy giant Gazprom in court, three months after the company faced a halt in deliveries.

At the end of December, Gazprom stopped supplying Overgas over what the Russian Foreign Ministry describes as ongoing commercial issues.

Since January 01, the joint Bulgarian-Russian company has been receiving gas from Bulgargaz, the state-owned supplier.

Gazprom's export company, on the other hand, owns a stake in Overgaz which it is intending to sell in the near future.

Svetoslav Ivanov, who works for one of the parent companies of Overgaz, has told the Bulgarian National Radio that the case does not get media coverage anymore, but the company is still facing trouble.

Overgas argued in December it had not been informed of Gazprom's intentions to halt supplies, insisting it was upholding to its long-term contract with the Russian energy holding that was due by 2019.

It maintains it has no standing debt to Gazprom.