MOSCOW, Sept 21 (Reuters) - The Russian government commission that monitors foreign investment will force public companies buying back shares from Western investors at a discount to return some of those securities to the stock market, a finance ministry official said on Thursday.

Retailer Magnit last week completed a $507 million buyback of blocked shares from Western investors at a 50% discount, a deal that could pave the way for more companies to follow suit.

Russia's presidential office is reviewing a request from oil major Lukoil to buy back up to 25% of its shares from foreign investors.

Ivan Chebeskov, head of the finance ministry's financial policy department, said there were no new developments on that case yet, but said government officials have been looking at smaller deals that would involve buybacks from foreign stakeholders.

"There were several such deals, only there was a decision on them that they should return some of these shares to the market," Chebeskov said.

Chebeskov declined to give more information or name specific companies.

Foreign companies concluded around 200 Russian asset sales between March 2022 and March 2023, the Russian central bank has reported, with about 20% worth more than $100 million.

Chebeskov said the foreign assets commission has held around 200 meetings in the last 18 months, issuing around 1,500 permits for foreigners' transactions, with the main goal of ensuring the stability of businesses whose foreign owners sell.

"So that people who work in these companies do not lose their jobs...so that technology does not leave, that production does not stop," he said.

Russia already demands 50% discounts and a budget contribution of 10%, termed an "exit tax" by Washington.

That 10% exit tax is sometimes higher, Chebeskov said, particularly when the industry and trade ministry is managing a transaction.

"This is de-facto becoming the benchmark to which the commission is starting to move," Chebeskov said. "There is no formalisation yet, but there possibly will be." (Reporting by Elena Fabrichnaya; Writing by Alexander Marrow; editing by Jonathan Oatis)