Duke Energy and Progress Energy have responded to federal regulators request for more information on their latest merger plan.
In a statement, the companies said they don't expect the Federal Energy Regulatory Commission's request to affect efforts to complete the merger by July 1.
They said the FERC's requests were common and "were technical and focused on the transmission-related models that Duke and Progress submitted as an exhibit to the March 26 revised mitigation plan. Many of our responses involved re-formatting data previously submitted to FERC as part of that filing."
In a letter Tuesday, the FERC gave the companies seven days to respond.
Under the plan submitted in March, the companies would spend about $110 million on seven transmission projects intended to bring competitors' power into the Carolinas, increasing market competition.
Duke and Progress have also signed power purchase deals with three wholesale electricity marketing companies that would be in effect until the transmission projects are finished.
FERC raised about a dozen issues in Tuesday's filing. Among them were questions about the companies' analytical models supporting the transmission projects.
FERC cited problems with models addressing competition concerns in Progress' Carolinas territory.