A three-centre phenomenological model, able to explain qualitatively the recently obtained experimental results concerning the quasimolecular stage of a light-particle accompanied fission process, was developed. A new minimum of a short-lived molecular state appears in the deformation energy at a separation distance very close to the touching point. The influence of the shell effects is discussed. The half-lives of some quasimolecular states which could be formed in the ¹⁰Be and ¹²C accompanied fission of ²⁵²Cf are roughly estimated to be the order of 1 ns, and 1 ms, respectively.