By Maria Kiselyova
MOSCOW (Reuters) - Pavel Durov, founder of Russia's biggest social network, said he sold his stake in VKontakte (www.vk.com) to an ally of tycoon Alisher Usmanov, the site's second-largest shareholder, who has long wanted to secure control.
Durov sold his 12 percent stake to Ivan Tavrin, the chief executive officer of Russian mobile phone operator Megafon, which Usmanov controls, Durov said on his VK page on Friday.
This means that Usmanov and his allies now control around 52 percent of the company.
According to business daily Vedomosti, the deal took place last month and was probably based on a valuation of $3 billion-$4 billion for all of VK, Russia's answer to Facebook.
Tavrin could not immediately be reached for comment. VKontakte's press office did not respond to an emailed request for comment.
VK is 39.9 percent owned by Russian internet group Mail.Ru, which is part owned by Usmanov and has long been seeking to increase its stake to gain control of the network of more than 100 million users.
In 2012, Mail.Ru handed Durov the voting rights to its stake, creating a partnership with effective majority control, but then said it still wanted to own a larger stake.
In April 2013, however, Russian investment fund United Capital Partners (UCP) bought out two other co-founders of VKontakte, becoming its biggest shareholder with a stake of 48 percent.
At the time, VK said Durov had no intention of selling his stake.
On Friday, Durov said his influence at VK would continue despite the sale.
"This change will hardly impact the governance of VKontakte - its board of directors has been paying attention to my opinion not because I own a stake but because I created this network and understand its deep mechanisms," Durov said.
UCP on Friday confirmed the change in ownership.
(Additional reporting by Douglas Busvine; Editing by Anthony Barker)