Carlos Slim’s America Movil formally launched its offer to acquire up to 27.7 percent of KPN today, despite the Dutch-based operator group protesting that the EUR8 per share offer undervalues the firm.

According to the Financial Times, the offer will commence at the start of trading today and close on June 27, though KPN says it will continue to explore other strategic options during the process.

Mexico-based America Movil announced its planned bid three weeks ago in what would be its first major foray into Europe. It already owns a 4.8 percent stake in KPN and may need to spend around US$3 billion to increase its stake to 27.7 percent, though this remains below the 30 percent threshold that would trigger the need to make a formal takeover bid for the remaining shares.

The EUR8 per share offer represented a 23 percent premium on KPN’s closing price when the deal was first announced; the shares were flat at EUR7.60 in early trading this morning, notes the Financial Times.

Speaking to the newspaper, Carlos Garcia Morena, America Movil’s CFO, said the Mexican firm planned to be a “long-term investor” in KPN and would explore synergies in areas such as equipment purchasing and content acquisition for pay-television.

Robin Bienenstock, an analyst at Sanford Bernstein, said the bid would almost certainly be successful barring a last-minute bid for KPN from Telefonica, which has reportedly been interested in buying a stake in KPN for some years.