Hancock Holding Co. added $45 million to the amount set aside to cover loan losses in the first quarter, saying oil’s prolonged downturn had downgraded the risk ratings on more than $300 million in energy debt.

Hancock said it had only recently discovered the downgrades. The company now expects it is unlikely to recover $58 million to $62 million in debt during the first quarter.

During a Jan. 22 conference call with investors and stock analysts, Hancock Chief Executive Office John Hairston said the company had written off just $3.75 million in energy-related loans since the downturn began in late 2014.

Hancock had reserved $78.2 million for loan losses in the energy industry, roughly 5 percent of energy loans.

At the time, Hairston said the company expected its total losses for energy’s downturn at between $50 million to $75 million, according to a transcript of the call by SeekingAlpha.com.

Hancock has branches in Mississippi, Alabama and Florida and Whitney Bank offices in Louisiana and Texas.