Telenor’s opposition to the deal -- which would see Vimpelcom taking a controlling stake in Egypt’s Orascom Telecom and all of Italy’s Wind -- means that all three independent Vimpelcom directors must back the long-running transaction.
The deal, which has been backed by the Kremlin, would make Russia’s Number Two mobile phone operator the world’s fifth largest.
Analysts said the move undermines the long-term stability of Vimpelcom by once again pitting Telenor against its other major shareholder Altimo -- the telecoms arm of Russia’s Alfa Group run by billionaire Mikhail Fridman.
The two owners fought protracted board and courtroom battles over strategy for years before a 2009 resolution.
Telenor spokesman Dag Melgaard said the deal did not make “strategic or financial sense” for shareholders.
Telenor has 36 per cent of voting rights in Vimpelcom and three of the nine Vimpelcom board members.