The present invention relates to a transition metal complex represented by the formula (I): ##STR00001## wherein M represents a Group 4 transition metal; --Y-- represents (a): --C(R.sup.1)(R.sup.20)-A-, (b): --C(R.sup.1)(R.sup.20)-A.sup.1(R.sup.30)--, (c): --C(R.sup.1)=A.sup.1-, or (d): --C(R.sup.1)=A.sup.1-A.sup.2-R.sup.30; A represents a Group 16 element and A.sup.1 and A.sup.2 each represents a Group 15 element; R.sup.1 to R.sup.9, R.sup.20, and R.sup.30 are the same or different and each represents an optionally substituted hydrocarbon group, etc.; and X.sup.1 and X.sup.2 are the same or different and each represents a hydrogen atom, a halogen atom, an optionally substituted C.sub.1-10 alkyl group, etc., and an intermediate product thereof, and a catalyst for olefin polymerization which comprises said transition metal complex as a component.