Catalyzes the electroneutral exchange or flux of physiologically important metabolites such as dicarboxylates (malonate, malate, succinate), inorganic sulfur-containing anions, and phosphate, across mitochondrial inner membrane (PubMed:9733776). Plays an important role in gluconeogenesis, fatty acid metabolism, urea synthesis, and sulfur metabolism, by supplying the substrates for the different metabolic processes (By similarity). (S)-malate(in) + phosphate(out) = (S)-malate(out) + phosphate(in) (S)-malate(in) + malonate(out) = (S)-malate(out) + malonate(in) (S)-malate(in) + succinate(out) = (S)-malate(out) + succinate(in) (S)-malate(in) + sulfate(out) = (S)-malate(out) + sulfate(in) (S)-malate(in) + 2 thiosulfate(out) = (S)-malate(out) + 2 thiosulfate(in) malonate(out) + phosphate(in) = malonate(in) + phosphate(out) phosphate(in) + succinate(out) = phosphate(out) + succinate(in) phosphate(in) + sulfate(out) = phosphate(out) + sulfate(in) phosphate(in) + 2 thiosulfate(out) = phosphate(out) + 2 thiosulfate(in) malonate(out) + succinate(in) = malonate(in) + succinate(out) Belongs to the mitochondrial carrier (TC 2.A.29) family.