BELGRADE, May 7 (Reuters) - Serbia is not satisfied with Hungarian oil company MOL's MOLB.BU proposals for the purchase of its sole refinery, NIS NIIS.BEL, whose Russian owners are seeking to sell their majority stake, the country's energy minister said on Thursday.

The Serbian government, representing the state's 29.9% stake in NIS, is involved in talks with MOL aimed at settling relations between Belgrade and the new prospective majority owner.

They are separate from MOL's negotiations with NIS's current majority owners, Russia's Gazprom GAZP.MM and Gazprom Neft SIBN.MM.

Following a meeting with MOL representatives in Belgrade, Dubravka Djedovic Handanovic said in a video on Instagram that the Serbian side was concerned about future operations "so that refinery processing ... covers the Serbian market to a certain extent."

The talks between Serbia and MOL also focused on past NIS obligations MOL should fulfil, Djedovic Handanovic said.

"Disagreements involved past obligations undertaken by NIS that are important to Serbia, and how to enable them to either be fulfilled or for the state to receive appropriate compensation," she said without specifying further.

She said Serbia remains committed to more talks.

MOL did not immediately respond to a Reuters request for comment.

Gazprom holds an 11.3% stake in NIS, while Gazprom Neft owns 44.9%.

The U.S. Treasury's Office of Foreign Assets Control imposed sanctions on NIS as part of wider measures targeting Russia's energy sector over the war in Ukraine and demanded the divestment of the NIS shares owned by Gazprom Neft and Gazprom.

MOL signed an agreement on January 19 to buy the combined Gazprom Neft and Gazprom stakes, and Washington gave the Russian companies until May 22 to complete the sale. Serbia also wants to increase its stake by an additional 5%.