For mobile companies that charge premium rates for voice calls, VoIP is a major threat as it offers consumers free calls over the Internet. With tariffs for voice products, both fixed and mobile, already falling fast through competition, regulatory pressure and new technology, VoIP could exacerbate the situation by potentially cutting tariffs altogether."Internet voice is going mobile," Jorma Ollila, Nokia chief executive said at the conference."Expect a mobile VOIP downgrade very soon," said Westhall Capital analyst Cyrus Mewawalla in a note entitled 'Nokia Opens The Floodgates to Mobile VoIP.' The investment implication? Stay away from companies who rely too heavily on voice revenues (especially wireless voice, where prices are up to 100 times higher than Internet prices)."He subsequently recommended selling Vodafone, Telecom Italia, China Mobile Ltd. and Taiwan Mobile Ltd.