PURPOSE: To provide a new compound useful as a component of a catalyst for polymerizing olefins such as an atactic polypropylene having a low molecular weight.

CONSTITUTION: A compound of formula I (R1 is H, 1-20C alkyl, 3-20C cycloalkyl, 6-20C aryl or the like; M is Ti, Zr or Hf; R2 is halogen, -OH, -SH, R1, -OR1, -SR1 or the like; R3 is CR, SiR, GeR or the like) e.g. dimethylsilandily-bis(fluorenyl)zirconium dichloride, is obtained, e.g. by reacting a compound of formula II with a compound of formula III which is formable an anion, then, reacting the resultant compound with formula R3X2 (X is halogen) and reacting the formed compound with a compound of formula IV which is formable a dianion.