PURPOSE: To obtain the subject carbonate having excellent properties in a molding operation such as blowing molding by reacting a specified carboxylic-acid- terminated linear polycarbonate with a polyepoxy compound.

CONSTITUTION: The objective carbonate is obtained by reacting at least one carboxylic-acid-terminated linear polycarbonate (A) with at last one polyepoxy compound (B) in an amount effective for branching. It is desirable that component A contains at most one carboxylic acid group at each terminal, and that component B is poly(O- or N-epoxyalkyl-substituted) cyclic amide, imide or imidate.