Russian internet investment fund Digital Sky Technologies has upped its stake in top-two portal and email host Mail.ru to 50.55 percent by buying 15 percent from Tiger Global Management. Business paper Vedomosti estimates the investment at $180 million to $200 million. Mail.ru had been planning a $2 billion IPO in London as Russia’s new-wave internet scene gets hotter and hotter, but there’s now some suggestion the IPO may not be necessary in light of the new cash. Other shareholders are South African media group Naspers (32.07 percent) and Tiger Global Management (13.4 percent), while Yakov points out Digital Sky already has stakes in social net Odnoklassniki.ru and Facebook-a-like Vkontakte.