Shares of NRG Energy Corporation surged as much as 9 percent on Tuesday after hedge fund titan Paul Singer's Elliott Management said it has partnered with Bluescape Energy Partners to push for changes at the integrated power company.
The partnership owns a combined 9.4 percent stake in NRG, having built up the position in recent months, according to filings with the Security and Exchange Commission. Elliott and Bluescape did not offer much detail about their plans for NRG, but said they are evaluating the nomination of one or more directors to NRG's board.
"The Group believes the securities of the Issuer are deeply undervalued and that there exist numerous opportunities to significantly increase shareholder value, including operational and financial improvements as well as strategic initiatives," Elliott and Bluescape said in a 13D filing.
In a statement, NRG said, "We are aware of the 13D filing that came in today. We are open to input from all our shareholders and we are committed to creating value for our shareholders."
Bluescape Energy is a Dallas-based private investment firm chaired by Charles John Wilder Jr., the former CEO and chief executive of Texas electric utility TXU Corporation, which was sold in 2007.
"The Group believes that Charles John Wilder, Jr. and his team have directly relevant experience in effectuating such improvements and are initiating a dialogue with management and the Board of Directors ... to address these opportunities as well as implement appropriate Board-level oversight," Elliott and Bluescape said.
The stock later pared its gains, but still ended the day 5 percent higher.
With Tuesday's gains, shares of NRG have risen more than 51 percent in the last year. Still, CNBC's Jim Cramer said on Tuesday the stock has more room to run under the right circumstances.
"This stock deserves to be much higher, but the current management doesn't know how to unlock value. A lot of value was locked unfortunately by David Crane, the previous CEO who had a grand vision — not unlike [Tesla CEO Elon] Musk — had a grand vision for solar. But solar turned out to be not that great for any of these guys," Cramer said on "Squawk on the Street."
Correction: This story has been updated to show Elliott Management and Bluescape Energy Partners own a combined 9.4 percent stake in NRG Energy.