The main reason for the widening gap is that growing numbers of foreigners are being employed in sectors with traditionally lower wages, such as cleaning.
However, discrimination also plays a part, says Statistics Finland researcher Antti Katainen.
The average monthly wages for foreigners at the end of 2007 was 2,579 euros, where for Finns it was 2,737 euros. The biggest gap - 7.7 percent - was to be found in the private sector, while the municipal sector has the smallest difference: 3.1 percent.
In some professions, foreigners are taking home bigger paychecks than their Finnish colleagues. This includes bus and tram drivers as well as cooks.
This is mostly due to the fact that foreign drivers work more late nights, weekends, and overtime than Finns do. As for the cooks, Finns tend to work in municipal kitchens while foreigners are employed in private restaurants mainly in the Uusimaa region.