Nokia last month announced a strategy overhaul, dumping its own software platforms and saying it would start to use Microsoft's Windows Phone.
Shares in Nokia, the national champion in Finland, have dropped more than 20 per cent since.
Nokia said topics to be discussed include the planned changes in organisation and work arrangements, but not potential job cuts.
Unions fear the changes could cost more than 5,000 jobs in Finland.
"Possible personnel reductions are not part of the consultation process at this stage, as we do not yet know how the operational changes will affect the number of personnel," said Nokia spokesman Doug Dawson.