Some of the region's most influential environmental organizations are asking N.C. regulators to impose additional conditions on the proposed merger between Progress Energy and Duke Energy before the two power companies are allowed to combine into the nation's largest electric utility.

The groups filed their request with the N.C. Utilities Commission on Monday, the deadline for participants in the merger proceedings to sway the state regulators in their merger review. The filing by the Environmental Defense Fund, Sierra Club, Southern Alliance for Clean Energy and the S.C. Coastal Conservation League was posted on the commission's web site this morning.

"The commission's decision in this proceeding will shape the energy future not only of North Carolina, but of the Southeast and the entire nation as well," the groups wrote. "Environmental Intervenors remain concerned that the proposed merger does not provide sufficient protections for North Carolina ratepayers or the environment."

The $26 billion merger could be just weeks away from final approval by the N.C. Utilities Commission after being approved recently by the Federal Energy Regulatory Commission in Washington. The issue before the N.C. commission now is whether to hold another round of public hearings or to rule based on hearings held last year and submitted legal briefs.