* Plater is current chief operating officer
* To take over CEO job on Aug. 1
* Move comes after previous CEO left unexpectedly in June (Adds details on Plater's contract, share price, background)
VIENNA, July 24 (Reuters) - Telekom Austria named its Chief Operating Officer Alejandro Plater as its new chief executive on Friday, around two months after Hannes Ametsreiter left the company to take the helm at Vodafone Germany.
Mexican tycoon Carlos Slim's America Movil owns around 60 percent of Telekom Austria and wants to use it as a platform to expand in Central and Eastern Europe.
Slim had introduced Plater as Telekom Austria's new chief operating officer in March, tapping the former Ericsson executive who had helped America Movil build mobile internet networks in Central America.
Plater, 47, who has been interim CEO since Ametsreiter's exit, will officially start his new job on Aug. 1, Telekom Austria said. Its management board will then comprise two executives, Plater and finance chief Siegfried Mayrhofer.
Plater's contract will run through March 2018, with an option for a two-year extension, it said.
Shares in Telekom Austria were down 0.9 percent at 6.13 euros by 1015 GMT, while blue-chip index ATX was up 0.1 percent. (Reporting by Shadia Nasralla and Maria Sheahan; Editing by Edward Taylor and Jane Merriman)