JACKSON, Miss. (AP) — Entergy Corp. will raise customer bills again starting later this month to pay the costs of Entergy Mississippi buying a share of the Grand Gulf nuclear plant from sister company Entergy Arkansas.

A residential customer who uses 1,000 kilowatt hours per month will see his or her bill increase $2.78 per month from the current amount, according to the Mississippi Public Service Commission. The commission voted 3-0 Tuesday to approve the increase.

In December, the commission approved a rate increase of $8.29 a month to cover higher natural gas costs as well as the company's recent purchase of a Jackson power plant.

The Grand Gulf purchase is supposed to save fuel costs in the long run. Entergy projects a savings of $346 million from 2013 to 2042.