UPDATE: Sibir Energy Headquarters Searched By Police

Russian law enforcement agencies Wednesday conducted a search at a subsidiary of London-listed oil firm Sibir Energy PLC's (SBE.LN), the company said in a statement.

The investigation took place at the office of subsidiary Magma Oil Company and was aimed at another Sibir subsidiary Moscow Oil and Gas Company, or MOCG. Investigators looked at documents relating to incidents surrounding MOGC in 2006 and to its predecessor Moscow Oil Company in 2002 and 2003.

Sibir Energy bought MOGC from the City of Moscow in 2007. It said the investigation wasn't related to either Sibir itself or to Magma, but didn't elaborate further.

Since April, Sibir Energy has been subject to a takeover attempt by oil major OAO Gazprom Neft (SIBN.RS), the oil arm of state-controlled gas firm OAO Gazprom (GAZP.RS). Gazprom Neft says it has accumulated a 49% stake in the company with the right to increase its stake further.

Sibir and Gazprom Neft jointly operate the strategically important Moscow Refinery. The Moscow city government, which holds an 18% stake in Sibir Energy, has repeatedly tried to block Gazprom Neft's efforts to take control of the 200,000 barrels of oil a day refinery.

Sibir Energy, which also operates the Salym fields jointly with Royal Dutch Shell PLC (RDSA), has been dogged by corporate governance issues since it engaged in controversial real estate dealings with core-owner Chalva Tchigirinski in October last year.

Trading in Sibir's shares have been suspended from London's AIM exchange since February pending investigations into erroneous disclosures regarding the real estate dealings.

Company Web site: www.sibirenergy.com

-By Jacob Gronholt-Pedersen, Dow Jones Newswires; [phone]; [e-mail]