While Proto-Finno-Samic is generally accepted to have formed a genetic group, further subdivisions up the tree until Proto-Finno-Permic (or even Proto-Finno-Ugric) may be controversial. The following is the supposed phonetic evolution of Proto-Finno-Ugric to the Proto-Finno-Permic stage (Sammallahti 1988):
· In stressed syllables *ë → *e̋, *ë̅ → *ō (through an intermediate *e̋̅?); *ë → *ŭ, *a → *u, although PFU *i had already started lowering towards *a.
· The consonantal paradigm remains largely the same, although *u̯ → *v (with secondary *u̯ developed word-initially in Proto-Permic).
· The phonotactic system is somewhat different from the previous one: there are several PFP stems with word initial *r; geminate consonants may have also contained *čč.