Karelian Diamond Resources said mining authorities had granted the company a reservation in the Liperi region of eastern Finland.
A review of positive past exploration results and airborne geophysics in the area led to the decision to apply for the reservation, the company said.
The Liperi region lay within a geological area known as a Craton, which straddled Russia and Finland.
Two world class diamond deposits, Lomonosov and Grib, had been discovered on the Russian side and were now in production.
A reservation has given the company exclusive rights to apply for an exploration permit within the reservation area.
At 2:28pm: (LON:KDR) Karelian Diamond Resources PLC share price was 0p at 3.1p