By Veronika Gulyas

BUDAPEST--Hungary's largest company and central Europe's biggest refiner MOL Nyrt. (MOL.BU) and Croatia once again couldn't get ahead with talks on MOL's Croatian subsidiary INA.

At the fifth round of talks about the Croatian company's future held on Friday, there was no progress in either Croatia buying back management rights and an ownership stake from MOL, nor in securing a favorable long-term relationship while keeping the status quo.

Talks in Zagreb on Friday relate to the spat between the Croatian government and MOL. Croatia wants to regain control of INA, in which it holds a 44.8% stake following INA's privatization in 2003. MOL owns a 49.1% share, plus management rights.

"Regrettably, once again we were not able to discuss business issues and, despite previous promises by the [Croatian economy] minister, we haven't heard any suggestions how the regulatory environment could be improved," MOL said in a statement after the talks in Croatian capital city Zagreb.

Croatian Economy Minister Ivan Vrdoljak said the government proposed setting up a new shareholders' agreement, while MOL said it would continue to develop INA and reiterated its openness to continuing negotiations with Croatia.

To date, MOL has invested a total of 1.4 billion euros ($1.96 billion) directly into the Croatian economy, the company said.

MOL and Croatia are involved in a bribery case in which, in 2012, former Croatian prime minister Ivo Sanader was convicted of accepting bribes while he was in office, to allow MOL to have management rights over INA, according to a Croatian court.

MOL has repeatedly said the case was politically motivated and denied all these allegations. The company said Zsolt Hernadi, MOL's chairman and chief executive has proven that the allegations are unfounded and the case is without merit.

Write to Veronika Gulyas at veronika.gulyas@wsj.com

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