Simon Potter (Photo: Simon Dawson/Bloomberg)

The Federal Reserve Bank of New York said two of its top officers are departing — including Simon Potter, who oversees its strategically vital trading desk — in a rare double exit from the senior ranks of the U.S. central bank.

Potter and fellow executive vice president Richard Dzina, who ran the bank’s financial services group, will both step down effective June 1, the bank said in a statement Tuesday. It will launch a search to find their successors.

Their departures — which between them take almost 50 years of New York Fed experience with them — come about a year into John Williams’s tenure as president of the bank.

Potter had been seen in some quarters as a potential contender to take the helm in New York before Williams, who was then head of the San Francisco Fed, won the pick.

The New York Fed is the most important of the 12 regional Fed banks because of its oversight of Wall Street and execution of monetary policy via the desk that Potter ran.

The abrupt departures come at a delicate time for the central bank as it finishes shrinking its balance sheet. The wind-down process, which Potter oversees as the head of the New York Fed’s markets group, will end later this year but policy makers have yet to decide important questions on the long-term maturity composition of its bond holdings.

“I’m very surprised that both of them would do this on the same day with three days notice,” said Tom Simons, a senior economist at Jefferies in New York.

Simons said Potter’s job, as head of the central bank’s open-market operations, is “arguably more important than being president of the some of the regional Fed banks.”

He said the departures are especially worrying for market participants given the uncertainty hanging over the New York Fed’s plan, in conjunction with the U.S. Treasury, to replace the scandal-tainted London InterBank Offered Rate with a new dollar-based benchmark rate, known as the Secured Overnight Financing Rate.

Potter was scheduled to give a speech in Hong Kong on May 30 on the transition from Libor but now won’t deliver those remarks, said New York Fed spokesman Jack Gutt.

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