UPDATE 2-TNK-BP billionaires say CEO exit could hit tax

(Releads with AAR letter, adds details, background)

By Robin Paxton and Katya Golubkova

MOSCOW, July 28 (Reuters) - Billionaire shareholders in Russian oil venture TNK-BP on Monday asked BP (BP.L) to disclose the whereabouts of Chief Executive Robert Dudley, saying his plan to run the firm from abroad could have tax implications.

TNK-BP CEO Robert Dudley left Russia on Thursday, citing a campaign of harassment as a bitter dispute between rival shareholders in the country's number three oil producer escalated. His work visa was due to expire on Monday.

Another senior TNK-BP executive, Chief Operating Officer Tim Summers, would be granted an extension to his visa, which had also been due to expire on Monday, immigration authorities said.

BP and the Russia-connected billionaires who share ownership of TNK-BP have been at loggerheads over management and strategy at their joint venture, which pumps a quarter of BP's global oil output and is one of the largest foreign investments in Russia.

AAR AS Ltd, the consortium representing the billionaires, said in a letter dated July 28, a copy of which was obtained by Reuters, Dudley's decision to manage the firm from abroad could have "significant negative tax consequences for the group".

"We are deeply alarmed that, if the centre of TNK-BP's management and decision-making is transferred to a country other than Russia, then the TNK-BP Group, or companies within the group, may become liable for the payment of profits tax or other taxes in that country," AAR said.

"We request that you immediately inform AAR as to Mr. Dudley's whereabouts, as well as BP's understanding of the tax implications of Mr. Dudley's decision to manage TNK-BP from his current undisclosed location," AAR said in the letter, which was signed by AAR Chief Executive Stan Polovets.

NO SHOW

Dudley had been summoned to appear at a Moscow prosecutor's office on Monday to answer questions on TNK-BP's labour practice. A spokeswoman for the prosecutor's office said neither Dudley nor his representatives had appeared.

The Russia-connected shareholders in TNK-BP have demanded Dudley's resignation, accusing the BP-appointed executive of poor performance and favouritism toward BP.

BP has denied both charges, accusing the Russian side of using illegal tactics to wrest control of the company. The dispute at the once-successful partnership is viewed by analysts as a key test of the investment climate in Russia under new President Dmitry Medvedev, who has pledged to ensure the rule of law to the country to make the economy more sustainable.

Meanwhile, Russian immigration authorities said they would grant a visa to Summers, the chief operating officer, allowing him to stay in the country. Applications by other expatriate employees were still being considered.

"There are no problems. We'll give him his visa tomorrow," Federal Migration Service spokesman Konstantin Poltoranin told Reuters.

"As far as the rest of the employees go, we are working on it. There are no conflicts," he said. (Additional reporting by Melissa Akin; Editing by Paul Bolding) (robin.paxton@reuters.com; +7 495 775 1242; Reuters Messaging: robin.paxton.reuters.com@reuters.net))