N.Y. Transp. Corp. Law § 101
Nothing in this article shall be so construed as to permit any such corporation to engage in manufacture or production, except for its own use, of power, heat, light, supplies and equipment or to carry on the business of generating, selling or distributing electricity for light, heat or power, nor shall the right, operation and use of such privileges be extended beyond the streets or marginal streets bounding or occupied by the property owned or operated by such corporation. No railroad corporation, and no corporation or joint-stock association engaged in carrying on an express business, shall either directly or indirectly, or through the medium of a holding company or otherwise, purchase, acquire or hold, any stock, bond or evidence of indebtedness issued by any such corporation.
N.Y. Transp. Corp. Law § 101