The Missouri Public Service Commission is allowing Ameren Missouri to issue up to $150 million in new debt, billed as a move that could benefit Ameren's customers in the long run.
On Thursday, the PSC modified an order it had issued just 15 days earlier.
The PSC vote Thursday afternoon continued its approval for Ameren to issue the debt, with conditions included in its June 1 order.
On April 29, Ameren had asked for the authority, saying the new debt would be used to refinance short-term debt.
The company's April application told regulators the "price to be paid to (Ameren) for the various series of the New Indebtedness will not be less than 92 percent or more than 100 percent of the aggregate principal amount." The June 1 PSC order included those restrictions and became effective last Saturday.
But on Monday, Ameren filed a new motion asking the PSC to modify its order because changing market conditions since April would help the company "yield a lower cost of debt."
In its four-page order Thursday afternoon, the PSC agreed "any savings recognized will ultimately benefit Ameren Missouri customers, as it would lower the cost of debt reflected in future revenue requirements in rate cases when the company's rates are reset."
The PSC's staff and the independent Public Counsel's office both supported Ameren's request to modify the order.
To allow Ameren to take advantage of market conditions quickly, the modified order was made effective the day it was approved, instead of the normal, 30-day waiting period.