Mass. Gen. Laws ch. 164A § 4
Notwithstanding any contrary provision of any general or special law relating to the powers and authorities of foreign electric utilities, but subject to the conditions set forth in this chapter, a foreign electric utility which is a member of the New England power pool shall, in connection with its participation in such pool, have in addition the power jointly with one or more other electric utilities, including at least one domestic electric utility, to construct, purchase, operate, maintain, use, own, mortgage, lease, sell, dispose of or otherwise participate in electric power facilities or portions thereof within this commonwealth or the product or service therefrom; provided, however, that nothing in this section shall be construed to authorize a foreign electric utility to sell electricity at wholesale or retail within this commonwealth except (i) as otherwise authorized by or under the general or special laws of this commonwealth other than by this chapter; (ii) in connection with sales of economy, backup and other energy pursuant to a New England power pool agreement; and (iii) for any sale or sales of capacity and related energy from a specifically identified generating unit which is an electric power facility.
Mass. Gen. Laws ch. 164A, § 4