MOSCOW (Reuters) - Russian state oil major Rosneft (>> Rosneft' NK OAO) on Thursday offered to buy out small shareholders in TNK-BP Holding (>> TNK-BP Holding OAO) but said it would pay less for the stock than the price at the time of the takeover in March.

Chief executive Igor Sechin said that Rosneft was not a "charity fund" when it bought TNK-BP and did not intend to buy out minority shareholders, raising complaints from them and questions from international investors about corporate governance in Russia.

Following the TNK-BP deal, Rosneft became the world's No. 1 oil producer by output, pumping 4.5 million barrels per day - nearly half of Russia's total - but its capitalization of $74 billion is a fraction of U.S. ExxonMobil's (>> Exxon Mobil Corporation).

"They have had increasing pressure from minorities and there is clearly a lot of feedback that it is damaging the wider Russia franchise," said one trader at a Western bank in Moscow.

Rosneft Vice President Igor Maidannik said that while the company has no legal obligations towards TNK-BP shareholders, the state-owned giant's shares are sensitive to the situation.

"We don't have any obligations. It would be a voluntary offer or, if a decision on a reorganization is taken, a conversion. We will see," he told reporters at TNK-BP's annual shareholders meeting.

Maidannik said he preferred the idea of a share swap, because buyouts "usually don't lead to the desired result".

GLIMMER OF HOPE

Maidannik's comments offered a glimmer of hope for smaller shareholders of TNK-BP, the listed unit of the Anglo-Russian venture bought by Rosneft for $55 billion, will not end up empty-handed. British oil major BP (>> BP plc) sold its 50 percent stake in TNK-BP for cash and Rosneft stock.

Based on TNK-BP's market capitalization of $21.6 billion, down 57 percent since October when the deal was announced, a buyout of about 5 percent owned by minorities would cost Rosneft approximately $1 billion. TNK-BP shares rose up 1.8 percent.

Minority shareholders welcomed the idea with caution, as Sechin has previously rebuffed such calls.

"I support the idea. Maidannik made a good move. He allowed everyone to express their views and gave hope. But I wanted to hear it from Sechin, given that the decision should be taken not by Maidannik alone," said Gennady Osorgin, a shareholder since 2005.

Maidannik, Rosneft's legal counsel, played down expectations that shareholders - including several leading global emerging markets equity funds - could expect a big payout.

"It has been obvious since the deal was announced that TNK-BP's capitalization would fall," said Maidannik. "Someone might have dreamed that a buyout could happen at the deal's price, but in my opinion that was a gamble."

Earlier this month, Rosneft recommended waiving 2012 dividends for TNK-BP, saying its own policy of paying out 25 percent of earnings as dividends could only be extended to TNK-BP after the deal closed on March 21.

Investors have shown concern that subsequent deals by Rosneft could treat minorities the same way.

Shares of Bashneft have fallen by 4 percent since Tuesday, when Russian business daily Vedomosti reported that Rosneft was interested in buying the company, which produces 300,000 barrels of oil a day, from Sistema (>> AFK Sistema OAO).

The report, denied by Sistema's majority owner Vladimir Yevtushenkov, has also sent Bashneft's non-voting preferred shares down by 15 percent.

Gathered at a central Moscow hotel on Thursday, TNK-BP minority shareholders grabbed sandwiches as they anticipated a tightening of purse strings from Rosneft.

"Today we are being fed but at the next meeting we may not be offered even a cup of tea," said Viktor Alexeevich, 65, while putting ham sandwiches and pies into a bag.

"I'm very disappointed that they (BP) left us - they set an example to the locals on how to do business. The dividends they paid proved that."

(Writing by Katya Golubkova and Vladimir Soldatkin; Editing by Douglas Busvine and Megan Davies)

By Katya Golubkova