North Carolina utilities regulators are disclosing internal materials collected from Duke Energy Corp. in an ongoing investigation into its takeover of Progress Energy.

The North Carolina Utilities Commission on Tuesday posted more than 600 pages of emails and other information Charlotte-based Duke Energy delivered to the regulator.

North Carolina’s utilities regulators and attorney general demanded documents as they investigate Duke Energy’s surprise decision to change a key detail of its takeover even as regulators were considering approval.

The few nuggets include Duke Energy CEO Jim Rogers explaining in May that two female executives left for other jobs after expressing concern that they wouldn’t be valued in the combined company scheduled to be headed by Progress Energy CEO Bill Johnson. Johnson was dumped hours after the merger closed last month.