Peter Weiland, the most senior risk officer in JPMorgan Chase's Chief Investment Office before the "London Whale" scandal broke last April, quietly resigned in October, according to a report released by the bank on Wednesday.

His resignation has not been previously reported in the press.

Weiland, who was the head of market risk for the CIO until mid-January 2012, was the most senior risk officer in the bank's moneymaking office when the derivatives trades that eventually cost it $6.2 billion were being made.

In mid-January 2012, JPMorgan appointed Irvin Goldman chief risk officer of the CIO, placing him in a position above Weiland. Goldman held that position until May.

The report JPMorgan released in conjunction with its fourth-quarter earnings cited failures in risk management inside the CIO and by JPMorgan's senior management.

"CIO risk management made a number of key missteps," the report said, adding that "the firm did not ensure that the controls and oversight of CIO evolved commensurately with the increased complexity and risks of CIO's activities."

The CIO lost $6.2 billion when positions in a small, opaque derivatives market quickly lost value under a squeeze by several hedge funds. From the time the squeeze was first reported in April to a series of midsummer statements by JPMorgan and CEO Jamie Dimon, a number of managers inside the bank lost their jobs or changed positions.

The bank conducted an internal investigation into the incident, and regulators in the U.S. and the U.K. opened their own inquiries. The bank revealed in July it had found evidence that some CIO employees in London may have tried to hide losses in the CIO's books by trying to mismark the values of some derivatives trades. An investigation by the U.S. Securities and Exchange Commission and the Federal Bureau of investigation is ongoing.

By at least August, Weiland had hired a lawyer to represent him in the investigations into the trading losses. He continued to work in risk management in the CIO until October, when he resigned.

Weiland's lawyer did not immediately respond to a request for a comment.

(Reporting By Emily Flitter; Editing by M.D. Golan)