UPDATE 1-Sibir says no bid approach from TNK-BP

* Newspaper report says $3.4 bln bid planned

* Source says TNK-BP execs haven’t discussed takeover

(Adds detail, background)

LONDON, April 14 (Reuters) - Russia-focused oil company Sibir Energy SBE.L said it had received no takeover approach from Russia's third-largest oil producer, TNK-BP, following a report TNK-BP was planning a 2.3 billion pound ($3.4 billion) bid. Britain's Sunday Times reported that German Khan, a large shareholder and key executive at TNK-BP, which is half-owned by London-based oil major BP Plc BP.L, had canvassed Sibir investors to accept a 6 pounds/share bid.

A spokeswoman for Sibir declined to say if it was aware of approaches to shareholders.

One industry source said a takeover of Sibir had not been discussed at the top of TNK-BP but added that, in common with their peers at other oil companies, executives at TNK-BP consider potential acquisitions regularly.

“They run the slide rule over companies all the time,” the source said.

The four Russian billionaires - including Khan - who own the other half of TNK-BP have reputations for independence and have in the past worked on strategic moves, such as a potential investment in Iraq’s Kurdish region, which TNK-BP’s board subsequently chose not to pursue.

Sibir’s shares were suspended in February after it discovered it was owed $325 million by 23.5 percent shareholder Shalva Chigirinsky.

Last week the company said it had sacked its Chief Executive Henry Cameron and that it was pursuing a legal claim against Cameron and Chigirinsky likely to run to $400 million.

Moscow Deputy Mayor Vladimir Silkin told Russia's Kommersant daily on Monday that the city has no plans to sell its 18 percent stake in Sibir to TNK-BP TNBPI.RTS.