** Mobile phone company's shares down 4.4pct in the London Stock Exchange and the Nasdaq
** Company is reviewing potential acquisitions, including ofU.S. billionaire John Malone-backed Liberty Global,Reuters reported on Friday, to boost its broadband and cablenetwork businesses
** Acquisition of Liberty is likely to face regulatoryscrutiny in countries where two companies compete with other,such as Germany, Britain and the Netherlands
** Company also considering deal to buy British broadbandcompany Talktalk Telecom Group Plc
** Liberty shares down marginally at $51.80 premarket on theNasdaq