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June 10 (Reuters) - Serbia's Russian-owned NIS NIIS.BEL, which runs the country's only oil refinery, has applied for a new U.S. licence to continue operations after June 16, when its current licence expires, the company said on Wednesday.

In its request to the U.S. Treasury's Office of Foreign Assets Control (OFAC), NIS highlighted "the importance of the regular work of NIS for the orderly supply of the domestic market" and pointed to advanced negotiations on changing its ownership structure, NIS said in a statement.

NIS is subject to U.S. sanctions imposed in October over its Russian ownership, part of broader measures targeting Moscow's energy sector following its invasion of Ukraine. Washington has been pushing for the divestment of the Russian stake, and NIS has secured a series of temporary waivers in the interim.

On Saturday, OFAC gave Hungarian oil and gas company MOL MOLB.BU until June 16 to continue negotiations to buy the 56.16% stake in NIS held by Russia's Gazprom Neft SIBN.MM.

Serbia holds a 29.9% stake in NIS, with the remainder owned by minority shareholders.