Metro Finland will now be published alongside Sanoma's existing daily freesheet, Uutislehti 100.
The Sanoma chief executive, Mikael Pentikainen, said: "Metro complements our existing products and its addition will broaden our offering."
Metro Finland is distributed in 18 towns and cities in the Uusimaa region of southern Finland. Net revenue from ad sales in 2005 was EUR5.8 million. It remains open to international advertisers booking deals through Metro International's sales network.