USA regulator FINRA says "The SEC's Regulation M is designed to prevent manipulation by individuals with an interest in the outcome of an offering, and prohibits activities and conduct that could artificially influence the market for an offered security."
The decision, says the SEC, fulfils the desire of Congress after the 2008 (sic) financial crisis to reduce reliance on the primary credit reference agencies.
The notice will be published in the Federal Register and will come into force 60 days thereafter.