NEW YORK — JPMorgan Chase & Co.’s third quarter profit fell by 17% from a year earlier, as the bank set aside roughly a billion dollars to cover potential losses in an economic recession that CEO Jamie Dimon has said could come in six to nine months.

The nation’s largest bank by assets posted a profit of $9.74 billion, or $3.12 a share, down from a profit of $11.69 billion, or $3.74 a share, in the same period a year earlier. The results did beat Wall Street’s expectations of $2.90 a share, according to FactSet.

While the bank grew revenue and loans in the quarter, any additional profit it made compared to last quarter were erased by credit losses. The bank added $937 million to its loan-loss reserves, which is money banks set aside to cover potentially bad loans, in what the bank said reflects “updates to the Firm’s macroeconomic scenarios.” The bank also charged off roughly $700 million in loans, up sharply from a year earlier.

“While we are hoping for the best, we always remain vigilant and are prepared for bad outcomes so we can continue to serve customers even in the most challenging of times,” Dimon said in a prepared statement.

The bank’s trading desks had a mostly successful quarter, despite the market’s volatility the past several months. Bond trading revenues rose 22% while equity trading revenues fell 11%.

Firm-wide, JPMorgan had revenues of $32.72 billion, compared to $29.65 billion in the same period a year earlier.