Two executives who helped steer Standard & Poor's through the financial crisis plan to leave the credit-ratings firm and its corporate parent, the latest stage in the company's gradual makeover.

Vickie Tillman, who served as S&P's executive vice president until 2009, is in talks to leave S&P parent McGraw-Hill, a person familiar with the matter said. She is currently head of global sustainability business development at McGraw-Hill.