Any Company registered under the said Act, and any other Company duly constituted by law previously to the passing of this Act, and consisting of seven or more shareholders, may at any time hereafter register itself as a Company under this Act, with or without limited liability, subject to this proviso, that no Company established for the purpose of Banking or Insurance shall be registered under this Act as a limited Company ; and that no Company shall be registered under this Act unless an assent to its being so registered has been given by threefourths in number and value of such of its shareholders as may have been present, personally, or by proxy in cases where proxies are allowed by the regulations of the Company, at some general meeting summoned for that purpose.