The parent company of Dayton Power & Light Co. reported stronger earnings Wednesday, but warned that the local utility continues to face business and regulatory challenges.

“We have not realized the anticipated benefits and cost savings of the DPL acquisition, and DPL continues to face business and regulatory challenges,” The AES Corporation said in its 2012 annual report to shareholders.

In November 2011, AES acquired DPL Inc., owner of DP&L, for $3.5 billion. In 2012, AES recorded what in accounting terms is called “a goodwill impairment charge” of approximately $1.82 billion for DPL, an indication AES believes it will be difficult to recover the cost of the acquisition.

DPL’s issues are important, AES said, because that could “adversely affect DPL’s ability to refinance certain debt (or to do so on favorable terms) which is due in the near or intermediate term.”

DP&L has debt maturities in 2013 totaling $771 million, including a $200 million revolving credit facility and a $101 million letter of credit facility, AES said. Some of these maturities are subject to a first mortgage.

DP&L intends to refinance the first mortgage bonds under terms that would also allow for the potential legal separation of the company’s electric generation assets, part of its transition to a competitive market for electricity. While favorable terms are probable, there are no guarantees, AES said.

Risks facing DPL include customers switching to other providers and state utility commission approval of a proposed but still pending Electric Service Plan that includes a charge designed to recover $138 million per year for five years from customers. DPL said it needs the charge, which amounts to a monthly average of $5 per typical household, as the utility transitions to a market system for electricity.

In spite of the warnings, AES said that the company posted a 22 percent increase in adjusted earnings per share of $1.24 for 2012 compared to 2011. It said that this year it expects adjusted earnings per share of $1.24 to $1.32.

Overall, utilities revenue for 2012 increased $1.6 billion, or 119 percent, from 2011 because of new business of $1.5 billion from the operations of DPL and higher prices of $68 million at Indianapolis Power & Light in Indiana. There were new retail customers added in the Illinois service territory served with power purchased by DPL.