State utility regulators unanimously voted Wednesday that Entergy’s shareholders and not its customers would have to cover an estimated $1 million mistake in publicizing a bond sale.

“This is not Entergy’s fault, but it is their responsibility,” said Clyde Holloway, of Forest Hill, one of the five elected members of the Louisiana Public Service Commission. The commissioners regulate what utility companies charge their customers.

Entergy is to refund customers on their October bills for interest accrued from Aug. 5 until the bonds are sold, according to the PSC order.

Only the roughly 665,000 customers of Entergy Louisiana LLC, which covers 46 parishes, will receive the refund. Most of the utility’s customers in the Baton Rouge area are serviced by Entergy Gulf States Louisiana LLC and were not part of the bond, and therefore will receive no refund.

A monthly surcharge paid by Entergy Louisiana will guarantee the $206 million loan. The bond money will reimburse what Entergy spent toward converting a natural gas generator at the Little Gypsy plant near LaPlace to use petroleum coke as fuel.

A mistake in the legally required publishing of Entergy’s intent requires the company to publish again. The mistake could cost about $1 million in additional interest and other expenses, depending on when the bonds are sold, according to the PSC staff’s calculation.

Pamela Mitchell, executive director for the Louisiana Press Association, has said her organization gave Entergy an incorrect list of “official journals,” in which Entergy is required by the state constitution to publish its intention to raise rates. Mitchell said Tuesday local governments in four or five parishes recently changed the status of “official journal,” causing the company to publish in newspapers that no longer carry the “official journal” designation.

The PSC also voted Wednesday to reauthorize the bond, which allows Entergy to restart the legal clock on the procedures it must complete before the bond can be offered for sale.