Telia Mobile, the cellular carrier subsidiary of Sweden’s largest telecommunications company, has signed an agreement with Globalstar Northern Europe Ltd. that will extend Globalstar’s satellite-based telephone service throughout Sweden.

Subscribers will use a dual-mode telephone that provides GSM cellular service and switches to Globalstar when it is outside of GSM coverage. They will be able to keep their GSM phone number and will have GSM features such as text paging, voicemail and roaming through Globalstar.

Pre-operational trials of the service will begin in early July, with commercial service starting in early September. Globalstar Northern Europe is a joint venture of the Finish GSM carrier Oy Radiolinja Ab and the Italian company Elsacom S.p.A., a Finmeccanica company.