Telefónica O2 Slovakia, the country’s youngest cellco, has reported that it had over 400,000 active mobile customers as of 19 April, out of a total of over 600,000 that registered for its pre-paid packages. The company launched commercial services in February with an offer of unlimited on-network calls for SKK2 (USD0.08) a minute. The GSM service is initially relying on a national roaming deal with rival T-Mobile Slovensko, but Telefónica O2 is in the process of building its own network, and aims to have over 400 base stations deployed by the end of September.