But she said the strain was not the H5N1 type which can infect humans and has killed 61 people in southeast Asia since 2003.
The final results of the analysis should be known in three weeks.
The announcement by the Finnish authorities was made a day after European Union veterinary experts met to consider steps after the appearance of bird flu in Russia.
They called on EU members to raise their guard against the spread of bird flu but declined to follow the Netherlands' lead and impose a ban on keeping poultry outside.
"A number of actions were agreed at the meeting, including a review of contingency plans and increased vigilance to ensure that existing measures such as import bans are fully enforced," the EU's executive commission said in a statement.
Before the meeting a Finnish agriculture ministry expert told AFP that the risks of the epidemic spreading to her country were remote.
"The migration routes of Russian birds do not go over Finland. Furthermore for reasons of climate we raise little poultry in the open air," Sirpa Kiviruusu said.
Since 2002 Finland has taken regular blood samples from poultry and also analysed the feathers of wild birds.
The 2006 operation, which led to the discovery of the virus in the gulls, has just begun.