NextEra Energy is seeking to acquire Dominion Energy in an all-stock deal valued at about $67 billion, creating a massive power company as the energy needs of artificial intelligence drive demand higher in the U.S. It is one of the biggest proposed mergers so far this year and would create the world’s biggest regulated electric utility business by market capitalization, the companies said on Monday. The combined company will serve approximately 10 million utility customer accounts across Florida, Virginia, North Carolina and South Carolina.