* Buy-out to cost Carlos Slim's America Movil up to $2 bln
* Purchase will help Slim build up European presence
* Offer will remain open for eight weeks (Adds that offer will remain open until July 10)
VIENNA, May 15 (Reuters) - America Movil has submitted its offer to buy the shares of Telekom Austria which the Mexican telecoms giant or its partner, Austrian state holding company OIAG, do not already own.
In an announcement in Austrian newspaper Wiener Zeitung on Thursday, America Movil's European unit said it had offered 7.15 euros ($9.80) a share for the rest of the Austrian telecoms company's stock, confirming the price it had announced last month.
The offer will remain open for eight weeks, expiring on July 10 at 17:00 Central European time, America Movil said in a statement on Thursday.
The buy-out will cost America Movil, controlled by Mexican billionaire Carlos Slim, up to $2 billion on top of about $1 billion the company has already spent on building up its 27 percent stake in Telekom Austria since 2012.
The purchase of Telekom Austria is a landmark for Slim and should allow him to build up a presence in Europe as he seeks to expand business away from his main market Latin America, where he is under increasing pressure from regulators.
Last month America Movil sealed a deal with OIAG to take effective control of Telekom Austria. OIAG owns 28 percent of the former state telecoms monopoly, and will retain the right to appoint the company's chief executive and chairman.
Slim also holds a large stake in Dutch telecoms firm KPN , but his bid to take over the company failed last year. ($1 = 0.7294 Euros) (Reporting by Angelika Gruber and Tomas Sarmiento; Writing by Dave Graham)