North Carolina case law provides that, although an insurer who has paid part of insured’s claim “has a direct and appreciable interest in the subject matter of the action” brought by-insured against tortfeasor, Burgess v. Trevathan, 236 N.C. 157, 161, 72 S.E. 2d 231, 234 (1952), the insurer is not a necessary party to the action, but only a proper party. New v. Public Service Co., 270 N.C. 137, 153 S.E. 2d 870 (1967) ; University Motors, Inc. v. Durham Coca-Cola Bottling Co., 266 N.C. 251, 146 S.E. 2d 102 (1966) ; Burgess v. Trevathan, supra. The addition of parties where they are not necessary is a matter within the trial court’s discretion, and the judge’s order refusing to join additional parties is not ordinarily reviewable. New v. Service Co., supra; Corbett v. Corbett, 249 N.C. 585, 107 S.E. 2d 165 (1959) ; Guthrie v. City of Durham, 168 N.C. 573, 84 S.E. 859 (1915). Defendant has not shown how the interlocutory order appealed from deprives it of any “substantial right.” G.S. 1-277. See Funderburk v. Justice, 25 N.C. App. 655, 214 S.E. 2d 310 (1975). Therefore, this appeal is premature and is dismissed.

Dismissed.