The structure of the linearizer of a connected complex Lie group

The Morimoto theorem states that each connected abelian complex Lie group $A$ can be decomposed into the direct product of a group on which all holomorphic functions are constant, finitely many copies of ${\Bbb C}^\times$, and a vector group. We prove that if $A$ is the complex linearizer of a connected complex Lie group then the last factor of the product is trivial.