The Federal Reserve Bank of New York added $83.1 billion in temporary liquidity to financial markets Thursday, as a top official said the central bank may keep adding temporary money to markets for longer than policy makers had expected in September.

The liquidity came in two parts. There was an overnight repurchase agreement, or repo, that totaled $48.8 billion, and a $34.3 billion 14-day repo intervention. That compared with the $46.6 billion in temporary liquidity the Fed added to money markets Wednesday. On Thursday, eligible banks took less liquidity than the central bank was willing to offer.

Fed repo interventions take in bonds from eligible banks in what is effectively a short-term loan of central-bank cash, collateralized by the securities. Banks eligible to access these operations are limited in the amount of liquidity they can tap from the Fed, and they pay interest to the central bank for accessing its money.

The Fed has been adding significant amounts of short-term liquidity to financial markets since September, when short-term interest rates surged unexpectedly. At the time, major banks that normally lend cash short-term to other financial companies pulled back, causing money-market rates to go up. Most notably, the federal-funds rate, a key focus of central bank policy, moved above its range.

When the Fed restarted its repo operations after a decadelong break, it said it expected to wind them down by the end of January as Treasury-bill buying bolstered underlying reserves levels. The Fed also said it hoped to end its balance-sheet-expanding Treasury bill buying by around June.