Any existing stock casualty insurance company, and any stock casualty insurance company formed under this act, having a paid up capital in excess of the minimum herein required, may reduce the excess, in whole or in part, in the manner hereinbefore provided for the reduction of capital stock by insurance companies. Any such company which has undertaken two or more kinds of insurance and wishes to discontinue a particular kind may withdraw the entire additional capital paid in on account thereof.
40 P.S. § 726