It's looking as though we all might be invited to a wedding -- figuratively, of course. In this case, the purported bride and groom will be Duke Energy (NYSE: DUK) and its fellow North Carolina-based utility holding company Progress Energy (NYSE: PGN).

According to preliminary numbers, Duke would pay $13.7 billion for the stock deal. In arriving at that number, Progress Energy shareholders would receive 2.6125 shares of Duke Energy common stock -- with a value of $46.48 -- for each share of Progress that they own. That would represent a 4% premium above Progress' Friday closing on the New York Stock Exchange. At the same time, Duke would assume $12.2 billion of Progress Energy's debt.

The combined company would become the largest U.S. power company, serving 7.1 million customers in North and South Carolina, Florida, Indiana, Kentucky, and Ohio. It would have the capacity to generate 57,000 megawatts of electricity (22,000 from Progress). It also would likely attain the financial strength to increase its dividend, a key consideration for those with a penchant for investing in regulated utility companies.

On Monday, when the deal was announced, Duke CEO Jim Rogers said, "It really enhances our ability to grow the dividend going forward. Our plans are to grow the dividend at slightly less than the growth in our earnings." Specifically, during the conference outlining the deal, the companies indicated that their objective would be to expand their annual per-share earnings by 4% to 6%.

From Duke's perspective, the merger would increase the percentage of its earnings that's derived from more stable regulated activities. That figure currently represents 77% of the company's total but likely would expand to about 85% with the Progress addition.

Of course, a key to getting the deal done would involve regulatory approval, which is not always a given with utility combinations. However, the combined company -- which would be called Duke Energy -- would be able to pass along $600 million to $800 million in saving to its Carolina customers during its first five years by combining the companies' costs. The prospect of savings of that magnitude would appear to increase the likelihood of regulatory approval in those two states, the only jurisdictions where such a blessing would be required.

Nevertheless, mergers between public utilities never quite fall into the slam-dunk category. For instance, in just the past few years, planned mergers between FPL Group (NYSE: FPL) and Constellation Energy (NYSE: CEG), along with another involving Exelon (NYSE: EXC) and Public Service Enterprise Group (NYSE: PEG), were scuttled by regulatory impediments. Duke and Progress hope to close their deal by year's end.

As a longtime admirer of Duke and CEO Rogers in particular, I urge Fools to watch closely the progress of this nascent deal. With the relative minimal need to clear regulatory hurdles, there could be a solid -- and obviously massive -- public utility in the gestation stage.