Bashneft says proven oil reserves to last 20 years

* Bashneft says has proven reserves of 1.27 bln barrels
* Proven, probable and possible reserves 2.13 bln barrels

* First independent audit in 12 years

* Bashneft shares rise nearly 10 percent


(Adds details, share price)

By Robin Paxton

MOSCOW, April 14 (Reuters) - Bashneft (BANE.RTS), a mid-sized Russian oil firm controlled by billionaire Vladimir Yevtushenkov, has sufficient proven crude reserves to maintain current output for two decades, the company said on Wednesday. Bashneft, which owns oilfields and refineries in the Russian republic of Bashkortostan, said its first independent audit in 12 years had revealed proven reserves of 1.27 billion barrels as of Dec. 31. Its Moscow-traded stock rose nearly 10 percent.

Bashneft's total proven, probable and possible reserves were revealed at 2.13 billion barrels by the audit, which was carried out by U.S.-based oil and gas consultants Miller and Lents under Petroleum Resources Management System (PRMS) criteria.

"At current output levels, the company's proven oil reserves will last for more than 20 years," Bashneft President Viktor Khoroshavtsev said in a statement. He added that the company would undertake regular audits from now on.

Bashneft is among a collection of mid-sized oil producers in Russia, which for the last seven months has been the only country pumping more than 10 million barrels per day of crude.

Bashneft, owned by industrial conglomerate Sistema (SSAq.L) (AFKC.MM), needs extra crude to feed its oil refineries. It plans to raise production by around 7.8 percent to 13.2 million tonnes in 2010 due to faster development of greenfield projects.

"The data that we received allows us to plan oil production more accurately," Khoroshavtsev said.

Sistema, whose main asset is top Russian mobile phone operator MTS (MBT.N), paid $2.5 billion for control of Bashneft and five other energy firms in which it already owned blocking stakes of up to 30 percent.

The company has also applied to Russia's Federal Anti-Monopoly Service for permission to buy up to 49 percent of another mid-sized Russian oil company, Russneft. [ID:nLDE5BE2G2]

By comparison, Russia's largest oil firm Rosneft (ROSN.MM) has proved reserves under the PRMS methodology of 22.858 billion barrels of oil equivalent (boe) [ID:nLDE6170IF].

Bashneft's shares rose 9.6 percent on the RTS index by 1130 GMT, far outperforming a 1.4 percent rise on the wider market . Sistema's stock rose 2.1 percent on the MICEX exchange versus a 1.5 percent rise on the wider market . (Additional reporting by Vladimir Soldatkin; Editing by Keiron Henderson)