Leading rating agencies on Thursday agreed to assist the New York attorney-general with his probe into the mortgage industry as they adopted reforms aimed at preventing “ratings shopping”.

Andrew Cuomo, the NY attorney-general, said the agreement with Standard & Poor’s, Moody’s Investors Service and Fitch Ratings, which ends the inquiry into the agencies, marked a “dramatic overhaul” and addressed “systemic flaws”. He said: “The reforms should help restore confidence in the marketplace.”