Standard & Poor’s is seeking voluntary buyouts from as many as 100 U.S. employees in what would be the biggest staff cuts since the financial crisis for the credit grader, according to a person with knowledge of the matter.

The reductions, part of a productivity plan being implemented by S&P President Neeraj Sahai, seek to reduce layers of management, said the person, who asked not to be identified because the matter is private.

The buyouts, accounting for about 6 percent of the ratings division’s staff, are the most wide-reaching changes yet under Doug Peterson, a former Citigroup Inc. executive who was named chief executive officer of S&P parent McGraw Hill Financial Inc. last year. He joined the firm in 2011 amid scrutiny of the credit grader’s role in the 2008 credit crisis.

Sahai, who also joined from Citigroup in January to take over S&P’s top job, is seeking to streamline operations at the unit, the person said. The New York-based company is offering the buyouts to employees with business titles of director and above across the ratings division, which includes operations staff.

Ed Sweeney, a spokesman for S&P, said he couldn’t immediately comment.