MOSCOW – OAO Vimpelcom, Russia’s second-largest mobile-phone company, was upgraded to “buy” from “neutral” at Bank of America Corp, which increased its price estimate to US$22 from $12. Vimplecom is the majority stakeholder in Sotelco, a Cambodia-based mobile phone company operating under the brand name Beeline and newest of nine operators in the Kingdom following its launch in May. The Moscow-based company's shares closed at $17.95 Friday on the NASDAQ stock exchange in New York after gaining 1.7 percent or $0.30.