That loan, previously undisclosed, was made by investment-management firm EIG Global Energy Partners, which was at the same time helping arrange a major $1.25 billion round of financing for Chesapeake itself.

The new loan brings the energy executive's total financing from EIG since 2010 to $1.33 billion and his current balance due to $1.1 billion, this person said. It was secured by McClendon's personal stakes in wells that have yet to be drilled by Chesapeake - and by his own life-insurance policy.

A spokesman for McClendon declined to comment; a spokesman for Chesapeake didn't respond to a request for comment.

The latest insight into McClendon's personal financial deals comes in the wake of an April 18 Reuters investigation that found McClendon had borrowed heavily against his interests in wells owned by Chesapeake, mostly from EIG.

Last week, Reuters reported that McClendon had co-owned and actively invested in a $200 million hedge fund that bought and sold the same commodities produced by Chesapeake.

An outcry over potential conflicts of interest in the loans prompted inquiries by the Securities and Exchange Commission and the Internal Revenue Service. It also spurred Chesapeake's board on May 1 to remove McClendon as chairman (though not as chief executive) and to declare an early end to a controversial perk at the center of the borrowings.

All told, McClendon has taken out loans worth $1.55 billion since 2009 from EIG and other lenders to fund his participation in Chesapeake's Founders Well Participation Program. That perk enables him to receive a stake of up to 2.5 percent in all the wells Chesapeake drills in return for shouldering the same percentage of the wells' costs.

The latest McClendon loan was arranged in late March through a McClendon-controlled company called Pelican Energy LLC, which was formed on March 6.

The deal was initially intended to be significantly larger, up to $750 million, said the person familiar with the transaction. It was scaled back last week after the Chesapeake board announced the early end to the well-stake perk, which is now slated to conclude in June 2014.

The newest financing for McClendon closed shortly before EIG joined with other investment firms and hedge funds, such as TPG Capital and Magnetar Capital, in purchasing preferred shares in a newly formed Chesapeake subsidiary that has an interest in some of the company's wells. EIG invested $100 million in that deal, called CHK Cleveland Tonkawa, which raised $1.25 billion for Chesapeake.

An EIG spokeswoman declined to comment on the newest loan or on concerns of some analysts over EIG's dual role as a financier to Chesapeake and its CEO.

In an April 23 letter to investors in two of EIG's investment funds, EIG chief executive officer R. Blair Thomas said it is "simply untrue" that there was any conflict of interest in its loans to McClendon and dealings with Chesapeake.

The Securities and Exchange Commission has opened an informal inquiry into Chesapeake's well program and the transactions involving McClendon.

In the letter, Thomas discussed two earlier loan deals that EIG had done with McClendon, involving McClendon-controlled entities called Larchmont Resources LLC and Jamestown Resources LLC. There was no mention in the letter of the financing deal completed in March to Pelican Energy.

The person familiar with the deal said Pelican was not mentioned in the letter because EIG clients "already knew about Pelican" and the loan hasn't been disbursed yet.

This person added that when Pelican was launched, EIG sent a letter and "information packet" to clients advising them of the new financing and opening the loan vehicle up to investor participation.

EIG, which spun out of the Los Angeles-based bond shop TCW in 2011, has $13 billion of assets under management.

In the latest $450 million financing, EIG secured as collateral all the assets of Pelican Energy LLC. These include McClendon's interests in wells Chesapeake might drill in 2013 and the first half of 2014. The EIG financing to Pelican will be used to enable McClendon to continue in the Chesapeake well program through June 2014.

For years, McClendon used companies he controls, including Larchmont, Jamestown and Arcadia Resources LP, to hold his stakes in the Chesapeake wells.

EIG funded Larchmont and Jamestown at $375 million and $500 million, respectively. EIG did not lend any money to Arcadia, which borrowed as much as $225 million in 2009.

The investors in the EIG funds that lent to McClendon include U.S. public pension funds, foundations and wealthy investors in Europe and Australia.

In his April 23 letter to clients, Thomas of EIG defended the two prior loans to McClendon, writing: "The crux of the story as it relates to EIG seems to be that we got too good a deal for our investors."

(Reporting by Jennifer Ablan; additional reporting by Brian Grow, Anna Driver and Jonathan Stempel; Edited by Matthew Goldstein and Michael Williams)

• A Permanent Economic Emergency