Blythe Masters, managing director and head of Global Commodities Group, JPMorgan Chase & Co., New York, right, testifies on Capitol Hill in Washington, Wednesday, Dec. 2, 2009, before the Senate Agriculture Committee hearing on over the counter derivatives and efforts to address systemic risk in the financial sector. From left are, CME Group Executive of Chicago Chairman Terrence Duffy; Intercontinental Exchange (ICE) of Atlanta Senior Vice President Johnathan Short; The Depository Trust & Clearing Organization (DTCC) of New York Managing Director Peter Axilrod, and Masters. (AP Photo/Manuel Balce Ceneta)

(Reuters) - Blythe Masters, who will leave JPMorgan Chase & Co after a 27-year career, is under investigation by federal prosecutors in Manhattan, Bloomberg reported citing two people with knowledge of the matter.

The probe was opened after a settlement last year with regulators that alleged JPMorgan manipulated power markets in the Midwest and California, the report said. (http://r.reuters.com/tur48v)

The bank agreed last July to pay $410 million to settle the case. While Masters was not cited for wrongdoing, her name appeared in the regulator's order a number of times.

It is not immediately clear what the Manhattan prosecutors are investigating.

JPMorgan was not immediately available for comment outside regular U.S. business hours.

Masters, who began her career at the bank with an internship in London, wanted to continue as the chief of the commodities business even after its sale to Geneva-based Mercuria Energy Group Ltd, Bloomberg said.

JP Morgan is selling its physical commodities to Mercuria for $3.5 billion and Masters is expected to leave the bank in a few months after assisting with the sale.

(Reporting by Arnab Sen in Bangalore; Editing by Joyjeet Das)