EUROPE’S top antitrust regulator has opened a full-blown investigation into Telefonica SA’s US$14 billion sale of British mobile phone operator O2, warning that the mobile telecom merger could lead to higher prices and less choice for U.K. customers.

    The move follows a series of warnings from top European Union officials, including the bloc’s antitrust chief Margrethe Vestager, that mobile phone mergers in already concentrated markets risked harming consumers.

    Scandinavian telecom firms Telenor ASA and TeliaSonera AB abandoned plans to combine their Danish operations in September after failing to secure approval from EU authorities.

    The European Commission, the bloc’s executive arm, said Friday that the sale of O2 to Hong Kong tycoon Li Ka-shing’s CK Hutchison Holdings Ltd. would create the largest mobile network operator in Britain, potentially removing an important competitor. O2 is Britain’s second-largest mobile operator and Hutchison already owns the fourth-largest operator, Three U.K.

    “The commission has concerns that the transaction would remove an important competitive force and that the merged entity would have limited incentives to exercise significant competitive pressure on the remaining competitors,” it said. (SD-Agencies)