Ellington

JACKSON, Miss. (AP) — A bond rating agency downgraded Mississippi Power Co.'s debt to the lowest investment-grade level, saying the election of two new members of the state Public Service Commission "increases regulatory uncertainty."

Moody's Investors Service cut the debt rating Thursday on the unit of Atlanta-based Southern Co., its second downgrade in two months. Another downgrade would push the utility's debt into "junk" status. That means buyers limited to investment-grade securities couldn't buy its bonds, raising borrowing costs.

The move comes before Tuesday's hearing by current commissioners on whether Mississippi Power spent prudently on $1.1 billion in equipment at its $6.4 billion Kemper County Power plant. That includes turbines that have been generating power since last year using natural gas. Mississippi Power wants commissioners to make permanent an 18 percent emergency rate increase.