Hello and welcome to the Byggahus forum!
The partition wall is definitely load-bearing. The house is about 9 meters wide and the upper floor is finished, so there's no doubt about it. If you want to remove part of the partition wall, it must be replaced by a beam. I'm doubtful that it can work well over such a long span. The dimensions of the beam will be very large. You might need to consider a pillar somewhere in the middle. I think you should reconsider the floor plan. Large open spaces don't always work out well.