The city of Oulu is to surpass Turku in population. The city is to merge with the towns of Haukipudas, Oulunsalo, Kiiminki and Yli-Ii by 2013.

Following the merger, Oulu will have 182,500 residents.

The town of Haukipudas voted to merge 26 to 17, while Oulunsalo voted 19 to 16 in favour of the union. Kiiminki voted 24 to 11 to join. Both Oulu and Yli-Ii voted unanimously in favour of the merger.

Currently, Oulu has 139,000 residents while Turku has around 176,000.

Turku, the former capital, is currently the country's fifth-largest municipality behind Helsinki, Espoo, Tampere and Vantaa.