If you are trying to partition the disk you are booting from, then no, it cannot alter it's partition map while booted. You will have to use some alternative boot device (ordinarily this would be a bootable CD, but you'll need to find some workaround like an external device).
Also, the utilities in OS 9 will only repartition that drive by erasing the whole thing. You will need to boot into a Linux OS with one of the Linux partition tools if you want to non-destructively alter that discs partition table (use something like GParted on a bootable UBuntu disc or something like that).