BELGRADE, March 27 (Reuters) - Serbian oil company NIS

, majority-owned by Russia's Gazprom Neft

and Gazprom, is likely to get a last-minute, 30-day

extension to its waiver from U.S. sanctions, the CEO of state

gas company Srbijagas said on Thursday.

The previous waiver is due to expire at midnight, and if it

is not extended NIS could face crude supply cuts. NIS operates

the only oil refinery in Serbia, which has annual capacity of

4.8 million tons and covers most of the Balkan country's needs.

"There will be more delays of sanctions ... , but we cannot

expect more than 30 days," Srbijagas CEO Dusan Bajatovic told

Belgrade-based Pink TV.

He did not say how he knew this information. Bajatovic is a

member of Serbia's co-ruling Socialist party and Srbijagas is

also a trade partner of Gazprom.

NIS did not immediately respond to a request for comment.

As part of its January 10 sanctions on Russia's oil sector,

the U.S. Treasury's Office of Foreign Assets Control gave

Gazprom Neft 45 days to exit ownership of NIS.

On March 19, NIS sought a 30-day waiver of the sanctions, an

extension of the first reprieve approved on Feb 27, to secure

more time to find a solution with the Russian companies.

On February 26, Gazprom Neft transferred stakes of around

5.15% in NIS to Gazprom in an attempt to ward off sanctions.

The transfer follows a similar change in 2022 when the

company avoided EU sanctions imposed on Russia over its invasion

of Ukraine.

Gazprom Neft now owns 44.85% of NIS, while Gazprom has

11.3%. The Serbian government holds 29.87%, and small

shareholders the rest.

NIS imports about 80% of its needs through Croatian pipeline

operator Janaf, with the remainder covered by its own crude oil

production in Serbia.