Mexican billionaire Carlos Slim's America Movil has made a €7.2 billion bid for the shares in Dutch telecoms group KPN it does not already own, challenging a rival offer for KPN's German business.
Spain's Telefonica last month made an $11 billion bid for KPN's prized German arm E-Plus, casting doubt over America Movil's European investments.
As well as a near 30% stake in KPN, America Movil has 24% of Telekom Austria and on paper has lost money on both deals.
America Movil said last week it would bid €2.40 per share in cash for the rest of KPN. That is just under a third of the €8 per share Slim paid in May last year when he started building his stake in the business.
The €2.4 price is a premium of about 35% over the average closing price of KPN's shares for the last 30 trading days, America Movil added.
It values the whole of KPN at about €10.2 billion compared to the €8.1 billion that Telefonica has bid for E-Plus.
America Movil said it had invited KPN's supervisory and management boards to meet "as soon as possible," to discuss the offer, aimed at achieving "greater operational co-operation and co-ordination between the two companies."
KPN said it had taken note of the offer and was studying it.