UPDATE 1-Two Russian billionaires named as bidders for Polyus stake
* Mutsoyev, Yushvayev looking to buy Polyus stake -paper
* Deal now before U.K. Takeover Panel
* Report fuels speculation of all-Russian gold merger
MOSCOW, Jan 29 (Reuters) - Two Russian billionaires have been named by a financial daily as the possible joint buyers of a 38 percent stake in Russia's largest gold mining firm, Polyus Gold International Ltd, in a deal now facing scrutiny by the U.K. Takeover Panel.
The Vedomosti daily reported on Tuesday that one of the bidders for tycoon-turned-politician Mikhail Prokhorov's $4 billion stake was Zelimkhan Mutsoyev, a lawmaker whose family controls the Regions Group of shopping centres.
The other was Gavriil Yushvayev, a former co-owner of juice and dairy firm Wimm-Bill-Dann, now part of PepsiCo. Mutsoyev's net worth has been put at $1.5 billion by Forbes magazine and Yushvayev's at $1.2 billion.
No comment was immediately available from Prokhorov's holding company, Onexim, but sources familiar with deal have told Reuters that two prospective Russian buyers had agreed purchase terms for the stake last month.
Sources have also said that the buyers were receiving financial assistance from Suleiman Kerimov, the billionaire backer of Russian top-flight soccer club Anzhi Makhachkala who already owns 40 percent of Polyus.
Kerimov's investment company, Nafta Moskva, could not be immediately reached for comment.
British regulators are seeking to establish whether the buyers are independent of Kerimov, or whether they are working together with him in a so-called "concert party".
In the latter case, the stake purchase could force a buyout of minorities at Polyus, which won a premium listing on the London Stock Exchange last year but has not pursued inclusion in the FTSE 100 index because its free float is too small.
Kerimov has teamed up with Mutsoyev before. Mutsoyev was a member of a group of investors that supported the 2011 takeover by Moscow-listed potash producer Uralkali of competitor Silvinit, a deal that was orchestrated by Kerimov.
Another of Kerimov's co-investors in Uralkali is Alexander Nesis. Nesis, the owner of ICT Group, is also a shareholder in Polymetal International Plc, another Russian gold miner that is in the FTSE 100.
Those business relationships have fuelled speculation that the buyout of the Polyus stake belonging to Prokhorov, could herald an all-Russian gold merger.
Shareholder sources at Polymetal have played down their interest in a tie-up, however, arguing that Polyus is over-valued and has a history of poor execution at its Siberian gold projects.
Shares in both companies have rallied sharply in London since news broke last week that British regulators were reviewing the sale of Prokhorov's stake. Polyus was valued at Monday's close at $10.6 billion, and Polymetal at $6.8 billion.