UPDATE 5-Russia summons TNK-BP CEO for questioning

(Adds news of Hayward meetings with Gazprom, top officials)

By Tanya Mosolova and Dmitry Zhdannikov

MOSCOW, June 5 (Reuters) - Russia will question the chief executive of oil major BP's (BP.L) Russian venture as part of a probe into tax evasion at a unit of the embattled company, which many analysts expect to fall under the control of a state firm.

TNK-BP said in a statement on Thursday that a local Interior Ministry department has issued a summons to TNK-BP Chief Executive Robert Dudley as part of a tax probe into OAO TNK's activities in 2001-2003.

Also on Thursday, BP's chief executive, Tony Hayward, held talks during a visit to Moscow with three key players in the intrigue surrounding TNK-BP -- Alexei Miller, the CEO of gas major Gazprom (GAZP.MM), Igor Sechin, the chairman of oil major Rosneft (ROSN.MM) and First Deputy Premier Viktor Zubkov -- a BP spokesman told Reuters.

A source familiar with the negotiations said separately that Hayward could meet on Friday with Mikail Fridman, one of the billionaire shareholders of TNK-BP who have faced off with BP in calling for Dudley's resignation.

The Wall Street Journal reported on Thursday that Hayward also met with another of the billionaire shareholders, German Khan.

People with knowledge of the situation said the authorities plan to question Dudley next week in a case seen as a test for investment in Russia under new President Dmitry Medvedev.

"This is exactly the kind of issue that is making Medvedev's life so difficult as he tries to rebrand Russia as an attractive investment location," said Chris Weafer, chief strategist at Moscow-based investment bank UralSib.

"The fate of TNK-BP is a major test for how the government views the investment climate."

Mounting pressure on TNK-BP, Russia's third-largest oil producer, points to the likelihood the firm will have to sell a stake to a state firm such as Gazprom, analysts said.

BP shares closed virtually flat in London at 582.0 pence.

Dudley's summons comes on top of other problems at the firm, including the arrest of a TNK-BP employee on an industrial espionage charge, a raid on the company's central Moscow offices and a court injunction to stop it using BP specialists.

"We confirm the information that Robert Dudley has received a summons to the Investigative division of the Main Department of the Ministry of Interior in the Central Federal Region," TNK-BP said in a statement on Thursday.

"Mr Dudley has been requested for questioning with regard to tax matters pertaining to OAO TNK activities in 2001-2003. We regard this event as a routine procedural matter which is not connected with current shareholders' discussions."

Dudley never worked at TNK, but became the head of TNK-BP in 2003, when the 50-50 joint venture between BP and a group of Russian billionaires was formed.