Duke Energy Corp. and Progress Energy Inc. on Monday, July 2, moved to close their merger after winning the final needed regulatory approval from the South Carolina Public Service Commission.

North Carolina Regulators approved the deal June 29.

The state approvals were the last regulatory approvals needed to consummate the deal. The Federal Energy Regulatory Commission gave final approval to the deal June 11 after requiring the companies to revise an earlier mitigation agreement addressing increases in market power the deal would give the merged company in the Carolinas.

The deal had been under regulatory review since January 2011, when the companies announced they would merge in a deal worth $13.7 billion in Duke stock and the assumption of $12.2 billion in Progress debt.

"There is an absence of harm to South Carolina ratepayers as a result of the proposed merger," the state's order said.

South Carolina regulators forced the companies to cancel plans to complete the merger over the weekend by announcing it would vote on the companies' joint dispatch agreement at a public meeting Monday. According to the Charlotte (N.C.) Business Journal, the meeting ended up lasting less than 10 minutes with discussion limited to Commissioner G. O'Neal Hamilton reading a two-page motion approving the companies' proposed "joint dispatch agreement" and Commissioner Lib Fleming praising the companies and declaring that "South Carolina will be well served by this merger."

A Duke Energy spokesman said Monday morning that the deal would be consummated "later today" and the companies would issue a statement Tuesday morning.

The joint dispatch agreement allows the separate utility operations of Duke and Progress to be run by a single owner and was necessary because the utility operations of the two companies will not be merged for several years.

According to the two-page order approved by South Carolina regulators Monday, placing the companies' power plants under the same umbrella will result in fuel savings and related benefits of at least $650 million over the next five to seven years. The companies promised that a minimum of $127 million of that savings will be passed to South Carolina customers.

The merged company also pledged to provide community support and charitable contributions in South Carolina worth $10.65 million over four years and to contribute $3.75 million next year to support workforce development and low income energy assistance programs in the state.

The ruling allows Duke to operate the plants jointly for a year, after which the company must seek permanent approval for the joint dispatch agreement.