MOSCOW, Aug 22 (Reuters) - Russian oil major Lukoil is asking Russian authorities for permission to buy back up to 25% of its shares from non-resident investors at a discount of at least 50%, the Interfax news agency reported on Tuesday, citing sources.

Lukoil, whose shares rose by around 4% on the news, intends to pay for the buyback using the group's foreign accounts and would therefore not need to enter Russia's domestic FX market, the sources said. (Reporting by Reuters; Writing by Alexander Marrow; Editing by Mark Trevelyan)