A corporation may authorize, at a meeting duly called for the purpose, an amendment of its articles of organization, by vote of a majority of each class of stock outstanding and entitled to vote thereon effecting any one or more of the following:
Any reference in this section to any change with respect to authorized shares shall be deemed to refer to and include both the unissued and the outstanding shares; provided, however, that any change which impairs or diminishes the preferences, voting powers, restrictions (including restrictions on transfer), qualifications, special or relative rights or privileges of any outstanding shares may be authorized only in accordance with the provisions of section seventy-one. The aggregate par value of shares becoming outstanding by virtue of any change or exchange effected pursuant to the provisions of this section or of section seventy-one shall not exceed the amount of capital shown on the balance sheet of the corporation with respect to the outstanding shares so changed or exchanged, plus the amount of any surplus which shall be appropriated to capital in connection with such change or exchange.
Mass. Gen. Laws ch. 156B, § 70