That all railroad companies incorporated or organized or which may be incorporated or organized under the laws of this state, or of this and any adjoining state (or of any adjoining state), which now or at any time hereafter may be, in possession of or operating connecting railroads in this state or states adjoining this state under lease in perpetuity or for a period of not less than twenty years, shall have power to purchase or sell the remaining interests, property and franchises of the lessors of such railroads situated in this or in such adjoining states, on such terms and conditions as may be agreed upon by the parties or their assigns to such lease: Provided, that the railroad company which purchases any railroad in this state shall operate such road and hold such property and franchises subject to all the rights, privileges, duties and obligations prescribed by the general railroad laws of this state enacted or which shall hereafter be enacted for the regulation, government, taxation or control of the railroads organized or which may be organized under the laws of this state. And provided further, that this act shall not be construed so as to permit such railroad company to purchase any parallel or competing line of railroad.