Mexican tycoon Carlos Slim's America Movil offered Thursday to buy the 45 percent of Telekom Austria not owned by it or its partner, the Austrian government holding company OeIAG.
Seeking to lock in its presence in Europe after being forced to give up its proposed takeover of Dutch operator KPN last year, America Movil said its offer for the Austrian company's shares would stay open for eight weeks.
The offer came three weeks after the pan-American wireless giant struck a deal to combine its 26.8 percent stake in Telekom Austria with the 28.4 percent held by OeIAG, giving it effective control.
The deal gave America Movil, also known by its stock symbol AMX, operational control of Telekom Austria, which has some 20 million mobile customers spread across Austria, Belarus, Bulgaria, Croatia, Serbia, Macedonia, Liechtenstein and Slovenia.
The two sides also agreed to pump another one billion euros ($1.4 billion) in capital into the carrier.
At the time of that deal, America Movil chief executive Daniel Hajj said the transaction would help "better position Telekom Austria as a more relevant player in the European telecommunication markets."
In October Slim, one of the world's richest men, was forced to abandon a multibillion-euro hostile takeover bid for KPN, one of the largest fixed and mobile operators in The Netherlands and the third-biggest in Germany and Belgium.
US-traded shares of America Movil were down 1.2 percent at $20.21 in late-morning trade in New York.
In Vienna, shares in Telekom Austria rose 0.25 percent to 7.13 euros after the America Movil offer, which had been expected.