Exelon Corporation, the largest operator of nuclear power plants in the U.S., terminated its offer to acquire rival NRG Energy Inc. with a simple and direct statement today after nine months waiting for negotiations.

“The NRG shareholders have spoken, and Exelon will move on. We wish NRG and its owners well,” said John Rowe, chairman and chief executive officer of Exelon in a statement today.

Now we can redouble our focus on Exelon’s stand-alone growth opportunities, Rowe added.

Exelon took the action after NRG's shareholders declined to elect directors backed by Exelon for NRG's board who were likely to push for the buyout of the company.

Exelon last offered 0.545 of a share of Exelon common stock for each share of NRG common stock, a bid 12 percent higher than the first offer made in October. NRG said the offer undervalued the company but Exelon's CEO today responded by saying his firm was unwilling to raise its price to a level that would undermine Exelon's own value proposition.

Exelon shares were trading up 2.61 percent or 1.36 to $53.41 each by 3:12 p.m. in the New York Stock Exchange. NRG shares were up 5.44 percent to $24.83 each.