Whenever a State law prohibits, or requires approval or authorization of, the ownership or operation by a single company of the utility assets of an electric utility company and a gas utility company serving substantially the same territory, it shall be unlawful for a registered holding company, or any subsidiary company thereof, by use of the mails or any means or instrumentality of interstate commerce, or otherwise -

(1)

to take any step, without the express approval of the State commission of such State, which results in its having a direct or indirect interest in an electric utility company and a gas utility company serving substantially the same territory; or

(2)

if it already has any such interest, to acquire, without the express approval of the State commission, any direct or indirect interest in an electric utility company or gas utility company serving substantially the same territory as that served by such companies in which it already has an interest