METAIRIE, La. -- Former St. Louis Rams coach Steve Spagnuolo has agreed to take over as defensive coordinator for the New Orleans Saints.

A person familiar with the decision told The Associated Press on Thursday about the hiring on condition of anonymity because the Saints have not announced it.

Spagnuolo, 52, was head coach in St. Louis the past three seasons and was fired in January after going 10-38 with the Rams. Before that he was defensive coordinator for the New York Giants, a stint that included a Super Bowl upset of the New England Patriots.

Gregg Williams, who was New Orleans' defensive coordinator the past three seasons, has joined Jeff Fisher's new staff in St. Louis.

Spagnuolo's Rams were one of three teams to beat New Orleans during the 2011 regular season