JACKSON, Miss. (AP) — The Mississippi Public Service Commission on Tuesday delayed hearings on whether Mississippi Power Co. has spent prudently in building the $5.5 billion Kemper County power plant.

Prudency hearings are a key step in the company collecting from its 186,000 ratepayers to pay for the plant, even though rates have already risen 18 percent. The unit of Atlanta-based Southern Co. is already absorbing $1.5 billion in overruns from the plant, but could be forced to absorb more if the commission finds spending was imprudent.