Constellation Energy is nearing an acquisition of Calpine Corp., which would value the company around $30 billion including debt, Bloomberg News reported, citing people familiar with the matter.

Constellation Energy is in advanced talks to acquire Calpine in what could be one of the largest takeovers in the power generation industry, according to people familiar with the matter. A deal by the Baltimore-based utility to buy Calpine would also generate a huge windfall for the company’s private equity investors Energy Capital Partners,