The transition metal dichalcogenides (TX2), such as tungsten disulfide (WS2), are quasi-twodimensional layered materials with a band gap in the visible/near infrared range. In a bulk form, the crystals are composed of tightly bound S-W-S monolayer units which, weakly bound to one another by van der Waals forces [1]. The resulted band structure is indirect and thus, the photoluminescence (PL) is extremely weak. The intercalation of a small amount of halogen molecules (Br2, I2 or Cl2) in-between the monolayer units nevertheless leads to a strong excitonic PL emission [2, 3].   In the past we reported that, in WS2 single crystals intercalated with Br2 molecules, the low-temperature PL spectra are dominated by two narrow lines A and B, and their energy emission located at approximately 0.1 eV below the indirect band gap [3]. Moreover, our temperature dependence of the PL decay times suggested the presence of a fine-structure very close to the low-energy A excitonic line. Since the fine-structure splitting of the impurity center (Br2) is influenced by the electron-hole exchange interactions, understanding the detailed energy structure of the exciton and the interactions in the center are crucial.   In this work we investigate the fine-structure splitting of exciton emission lines related to Br2 molecules in WS2 single crystals using high magnetic fields up to B = 28T. We show that in a Faraday configuration, where propagation vector of light k is parallel to the magnetic field B, the low-energy A line shifts linearly with the magnetic field strength and exhibits a splitting which originates from the magnetic-field induced brightening of the an intermediate optically-inactive excited state A* (see figure). In contrast, the magnetic field has little effect on the second zerophonon line B observed in our PL spectra. Our high-magnetic field results confirm the existence of a forbidden radiative transition previously revealed in the PL-decay-time temperature dependence data [3], and elucidate the influence of the electron-hole j-j coupling on the exciton energy structure. Acknowledgment: This work was supported by the state grants in the framework of institutional projects of the Institute of Applied Physics of the Academy of Sciences of Moldova 15.817.02.06F.