Anne,
I agree with Tmaritta, Cathy and Max, it certainly has the look of Riihimaen.
There is (I think) the same olive green one
here, pictured with another Riihimaen vase of the same colour; this second vase is, I think, definitely Riihimaen - it normally has the 'Polar Bear' stamp. The colours look identical.
robbo