Marc Lipschultz, the head of energy investments at KKR & Co. LP who helped put together the world's largest leveraged buyout only to see it go bust, is leaving to start a credit fund, the private equity firm announced to its fund investors.

The change comes as KKR and other private equity firms are trying to recover as much of their investments in the energy sector as possible following a rout in oil prices. They are also looking to invest new money in assets that now appear cheap.

Lipschultz will leave KKR this month to start the new fund with Doug Ostrover, a former executive of private equity firm Blackstone, who helped to found its credit business, GSO Capital, KKR said in a memo to investors on Feb. 2.

Robert Antablin was named head of KKR's Americas energy private equity team, while David Rockecharlie is the new head of energy real assets, primarily focused on investing and building the firm's Energy Income and Growth Fund.

Raj Agrawal and Jesus Olmos were named global co-heads of infrastructure.

As one of the world's largest private equity firms, KKR, which managed $98.7 billion as of the end of September, has made several big energy investments under Lipschultz. But it is also nursing losses. Its Natural Resources Fund had a negative year-to-date return of 33% as of Oct. 27, KKR said in its most latest quarterly earnings.

KKR teamed up with peers TPG Capital LP and a unit of Goldman Sachs Group Inc. in the record $45 billion leveraged buyout of Texas power utility TXU Corp. in 2007. TXU, which subsequently became Energy Future Holdings Corp., filed for bankruptcy in 2014.

Lipschultz also oversaw KKR's investment in the $7.2 billion leveraged buyout of U.S. oil and gas producer Samson Resources Corp., which filed for bankruptcy last year.

Lipschultz, who has been with KKR for 21 years and founded the firm's energy real assets and infrastructure businesses, could not be reached for comment.

"Knowing Marc as well as we do, we have every confidence his new venture will be a great success and we look forward to KKR doing business with Marc's new firm," KKR founders George Kravis and Henry Roberts said in the memo on Feb. 2.