Clean Harbors Inc.’s chief financial officer, Robert Gagnon, has resigned.

The Norwell, Mass.-based hazardous waste management firm said its board designated James Rutledge, currently vice chairman, president and chief operating officer, to resume his role as chief financial officer, which he held from 2005 to August 2012, according to a company filing with the Washington-based Securities and Exchange Commission. His role now will not include the title of chief operating officer.

Gagnon will continue to perform “transitional services” for Clean Harbors until March 31. The company said Gagnon did not resign because of any disagreement with the firm, “and we thank him for his contributions to the company.”