BELGRADE (Reuters) - Serbian oil company NIS, majority-owned by Russian Gazprom Neft and Gazprom, has submitted a second request to the U.S. for a waiver of sanctions, the CEO of state gas company Srbijagas said on Wednesday.

The sanctions could result in crude supply cuts for NIS, which operates a single oil refinery in Serbia with annual capacity of 4.8 million tons that covers most of the Balkan country's needs.

The U.S. Treasury's Office of Foreign Assets Control (OFAC) initially placed sanctions on Russia's oil sector on January 10, and gave Gazprom Neft 45 days to exit ownership of NIS.

"Through their (NIS) lawyers, ... they have informed OFAC they were seeking a delisting from the sanctions list," Srbijagas CEO Dusan Bajatovic told RTS public broadcaster. Srbijagas is also partnered with Gazprom.

After the first request by NIS for a sanctions waiver on February 4, the OFAC delayed sanctions for 30 days on February 27 to allow the company to find a solution with the Russian companies.

"We all know that whatever we do, we can't finish it in 30 days," Bajatovic said, indicating the time frame was insufficient for the company to make the adjustments needed.

On February 26, Gazprom Neft transferred stakes of around 5.15% in NIS to Gazprom in an attempt to ward off sanctions.

Bajatovic said on Wednesday that such a move should have been sufficient to secure removal of sanctions.

The changes mean Gazprom Neft no longer has an absolute majority in NIS. They follow a similar change in 2022 when the company avoided EU sanctions imposed on Russia over its invasion of Ukraine.

It was unclear whether a similar move would satisfy U.S. authorities.

Gazprom Neft now owns 44.85% of NIS, while Gazprom has 11.3%. The Serbian government holds a further 29.87% of stakes, with small shareholders accounting for the remainder.

NIS imports about 80% of its needs through Croatia's pipeline operator Janaf, while the remainder is covered by its own crude oil production in Serbia. In 2024, the two companies agreed over the transport of 10 million tons of crude oil by December 2026.

Last week, Croatia's economy minister Ante Susnjar said Janaf was mulling the purchase of entire Russia's stake in NIS.