Adds comments from MOL official in paragraphs 10-11, changes dateline to BELGRADE

By Aleksandar Vasovic and Angeliki Koutantou

BELGRADE, May 15 (Reuters) - Serbia will submit its final proposal to MOL MOLB.BU on Friday concerning the Hungarian oil company's bid to take over NIS NIIS.BEL, operator of the Balkan nation's sole refinery, its energy minister said.

Russia's Gazprom Neft SIBN.MM and Gazprom GAZP.MM agreed to sell their 56% majority stake in NIS to MOL in January after the U.S. demanded the divestment of Russian-owned shares due to sanctions over Moscow's war in Ukraine.

"We had intensive discussions with representatives of MOL yesterday and the day before yesterday. We agreed on certain issues," Energy Minister Dubravka Djedovic Handanovic was quoted as saying by Serbia's Tanjug news agency.

"There are a few open issues left, and the most important issue for us is the future operation of the refinery."

The government will give its final position on NIS to MOL by the end of the day on Friday, and MOL's board will take a decision on the proposal on Monday, she said.

She did not give further details of what would be included in the proposal.

TALKS FOR A DEAL COME DOWN TO THE WIRE

Washington has given the Russian companies and MOL until May 22 to complete the sale, which will require Serbian government consent due to the state's 29.9% stake in NIS.

The talks between MOL and the Serbian government, which wants to increase its stake in NIS by 5%, are separate from the Hungarian company's purchase negotiations with Gazprom and Gazprom Neft.

In addition to a green light from the Serbian government, a MOL spokesman said the transaction will also require approval by the U.S. Treasury's Office of Foreign Assets Control (OFAC).

Speaking at a business forum in Belgrade on Friday, Gyorgy Bacsa, MOL's chief strategic officer, said the company was still speaking with both the Russian shareholders and Serbia and hoped OFAC would allow additional time for talks.

"If there is major progress until (May) 22, the recent practices ... show that a reasonable timeframe will be granted to make it all happen," he said. "We are interested in making a good agreement, my colleagues are in Belgrade."

Djedovic Handanovic said earlier this week that Serbia was not satisfied with some of MOL's proposals during their talks.

The U.S. imposed sanctions on NIS in October due to its Russian ownership as part of wider measures targeting Moscow's energy sector.

NIS, however, has secured a series of waivers from OFAC.