Abstract It is well known that linear phosphonitrilic chloride (LPNC) is formed by reacting cyclic phosphonitrilic chloride with phosphorus pentachloride. From the point of view that this oligomerization is a kind of telomerization, we synthesized another LPNC by the use of phosphorus pentabromide, as a telogen, in place of phosphorus pentachloride, and treated the new LPNC with a nucleophilic reagent such as diethylamine or aniline to displace both chain ends and attained considerable improvement of its thermal and hydrolytic stabilities.