The New York Fed, which serves as the US central bank's eyes and ears on Wall Street, will split a powerful role that oversees both market operations and the Fed's massive bond holdings, it said on Wednesday.

The Federal Reserve Bank of New York said it planned to hire two people to replace Simon Potter, a longtime staffer whose departure was announced in May.

Potter managed the US central bank's portfolio, including trillions in bonds bought to support the economy after the 2008 global financial crisis, using its holdings to influence interest rates and other markets and advising the Fed's policy-setting committee.

He was also in charge of the New York Fed's Markets Group, which trades in debt markets, manages relationships with Wall Street and provides banking services to the US government.

Those responsibilities will now be split between two jobs: one focused on the portfolio management role of turning Fed policy into action, and the other focused on the Markets Group's overall operations, policy, staffing and technology.

The changes come at a critical time for the Fed, which cut rates last week for the first time since 2008 and is managing division over how to respond to risks including a deteriorating US-China trade relationship and signs of a global slowdown. The Fed is also wrestling with how to manage nearly $4 trillion assets to prepare for the next downturn.

The shift also marks a new direction after just over a year in the role for the New York Fed's leader John Williams, an accomplished monetary economist.

Williams and other Fed officials have drawn scrutiny and some criticism for their communication with markets.

The New York Fed was compelled to issue a rare clarification last month after Williams roiled markets with a speech that the regional central bank said was meant to be academic and not directed at current policy debates.

Potter's departure was announced at the same time as that of the head of the Financial Services Group, Richard Dzina. Neither men commented on the reasons for their departures.

In its statement, the New York Fed said the changes would help the bank "best meet its critical responsibilities," and said it was using a search firm to draw up a list of candidates for the roles.