A bridged metallocene compound of formula (I) wherein: M is a transition metal; X, is a hydrogen atom, a halogen atom, or a hydrocarbon group optionally containing hetematoms; L is a divalent bridging group; R1 is a linear C1C40 hydrocarbon radical optionally containing hetexoatonis; T1, T2, T3 and T4 are an oxygen or sulfur atom or a C(R18)2 group with the proviso that at least one group between T1 and T2 is an oxygen or a sulfur atom; wherein R18, are hydrogen atoms or a C1-C4O hydrocarbon radical; n is 1, 2 or 3; R4 is a hydrogen atom or a C1-C40 hydro carbon radical; W is an aromatic 5 or 6 membered ring.