Mark Adelson, Standard & Poor’s chief credit officer until being demoted last year, left the ratings company.

Adelson, who was reassigned to a research role in December after helping overhaul the company’s methods for rating governments, banks and bonds backed by assets such as mortgages, departed this week, said Catherine Mathis, a spokeswoman for S&P, declining to comment further. Adelson declined to comment.

Douglas Peterson, who took over as president of the unit of McGraw-Hill Cos. in September, has been appointing new executives as S&P attempts to win market share after a series of high-profile decisions that roiled markets around the world.

Last year, he fired David Jacob, who had been head of structured finance since 2008 and worked as a consultant with Adelson before that.