NEW YORK (AP) — The president of Standard & Poor's is stepping down, an announcement coming only weeks after the rating agency's unprecedented move to strip the United States of its AAA credit rating.

The McGraw-Hill Cos., the parent of S&P, said late Monday that Deven Sharma will be replaced by Douglas Peterson, now the chief operating officer of Citibank N.A., Citigroup Inc.'s chief banking arm.

Sharma, 55, "was ready for new challenges" after helping S&P separate its data, pricing and analytics business from its ratings business, McGraw-Hill said in a statement. The company unveiled that restructuring at S&P late last year.

Peterson, 53, will take over the helm of S&P starting Sept. 12. Sharma will stay on as an adviser at the parent company until the end of the year.

McGraw-Hill's statement did not mention of the Aug. 5 downgrade that sent shock waves through global financial markets and was sharply criticized by the Obama administration, which said the agency's analysis was fundamentally flawed. Other major rating agencies have maintained their AAA ratings on the U.S.

It also did not refer to recent reports that the Justice Department was investigating whether S&P improperly rated dozens of mortgage securities in the years leading up to the financial crisis in 2008. Those reports sent McGraw-Hill's shares tumbling last week.

The company said only that Sharma was eager to pursue other opportunities.

"S&P will continue to produce ratings that are comparable, forward looking and transparent," McGraw-Hill CEO Harold McGraw III said in announcing the leadership change at the agency.

Sharma joined S&P in 2006 and was named president the following year. Before that, he was executive vice president, global strategy, at McGraw-Hill for five years.

Peterson was the CEO of Citigroup Japan before taking on his current role at that company.