Ameren Missouri is seeking approval to add about $1.50 to customers' monthly electric bills.
The Missouri Public Service Commission says Ameren wants to adjust the monthly fee that compensates the utility for changes in fuel costs at its power plants among other things.
The PSC says the proposal would increase the fee on an average residential customer's electric bill to $5.17 from the current $3.63 a month. It would take effect in October.
The proposed fee increase comes as Ameren Missouri already is seeking approval in a separate case to raise its electricity rates. The PSC also is hearing testimony in a case filed by Noranda Aluminum and other consumers alleging that Ameren's rates should be reduced because it's earning more than allowed.