DAYTON — The Public Utilities Commission of Ohio on Tuesday approved the $3.5 billion merger of DPL Inc. and Virginia-based AES Corp., giving the last regulatory approval that had been needed for the transaction to take place.

The merger will make DPL and its Dayton Power and Light Co. subsidiary part of AES, a Fortune 200 company based in Arlington, Va., that has electricity generating and distributing operations on five continents. That will end DP&L’s century of existence as an independent company.

The merger, first announced in April, will require AES to pay $30 in cash for each outstanding common share of DPL stock. AES also agreed to assume $1.2 billion in debt. The companies haven’t disclosed a date for closing the deal.

DPL shareholders had already approved the merger. The PUCO, in approving the deal, accepted three separately negotiated agreements designed to benefit DP&L’s ratepayers, employees and the city of Dayton.

Those agreements state that:

• AES will not pass along to DP&L ratepayers any expenses directly related to the negotiation, approval and closing of the merger.

• AES will keep DP&L’s operating headquarters in Dayton for at least five years after the merger.

• DP&L will not implement layoffs that would reduce the utility’s approximately 1,500-person work force to less than 90 percent of that employment level for at least three years.

• DP&L will commit $700,000 to Dayton for economic development, $400,000 to help low-income customers with energy costs, and $75,000 for the Ohio Hospital Association’s energy efficiency and energy demand reduction programs.

Still to be decided is whether Paul Barbas, the DPL president and chief executive officer who negotiated the merger with AES, and other senior DPL leadership will remain with the company after the transaction closes. Barbas and 10 other senior DPL executives could receive as much as $41.9 million combined in parting payments if AES asks them to leave the company, according to DPL’s regulatory filings with the U.S. Securities and Exchange Commission.

DP&L’s electric rates are locked in through the end of 2012, having already been approved by the PUCO.

Contact this reporter at (937) 225-2242 or jnolan@DaytonDailyNews.com.