RALEIGH, N.C. (AP) — Standard & Poor's says it has lowered the credit rating for Duke Energy Corp., citing the utility's lack of transparency in hiring a new CEO.

In a statement issued Wednesday night, Standard & Poor's said the lack of transparency significantly heightens regulatory risk for the company.

The company has said it made a good faith effort in appointing a new head and expressed disappointment in the decision.

The move by S&P follows news of a shareholder lawsuit using sworn testimony by Duke Energy executives and directors to support claims that investors were misled by a surprise shuffle of top executives.

Duke stock is down 6 percent since the merger.