As a very rough calculation with rounded numbers: In the original acquisition announcement, Kesko estimated a potential share issue of 500–700 million euros. There are approximately 400 million shares outstanding. If they wanted to raise that through a rights issue, it would be about 1.25–1.75€ per share.
As already speculated above, there are, of course, no guarantees that the share issue will end up being that size or that it will even be a rights issue (as opposed to, for example, a directed share issue).