Two months after a bombshell lawsuit accused former chief executive Aubrey McClendon of stealing trade secrets, Chesapeake Energy has settled with a key defendant: an Ohio drilling venture that McClendon founded.
In a surprise announcement Tuesday, the privately held drilling entity American Energy-Utica and the natural-resource investor Energy & Minerals Group, one of AEU's major investors, announced a "confidential settlement" with Chesapeake.
The settlement, which the companies said involved the assignment of 6,000 acres of land in a key Ohio county and a combination of cash and "contingent cash payments" amounting to no more than $25 million, effectively removed AEU from the case. Litigation remains against McClendon, his privately held drilling operator American Energy Partners and other defendants, the announcement said. EMG, the biggest investor in AEU, helped broker the settlement.
McClendon, who was forced to retire as head of Chesapeake in April 2013, was replaced as CEO of AEU in December but continues as a director of the parent company and chairman of American Energy Partners' other subsidiaries.
News of Tuesday's deal drove up shares of Chesapeake to more than $15 per share. At the same time, it removed a legal risk that has put a damper on fundraising efforts for McClendon and his subsidiary drilling companies, including AEU.
But within minutes of the Utica announcement, McClendon fired back, asserting he had not approved the settlement and had been shut out of the negotiations.
"AEU apparently chose to settle with Chesapeake before any discovery was taken, evidently for the business purpose of mitigating further damage that Chesapeake's litigation has been having on AEU's business and financing activities," McClendon said. He added that he and his parent company, American Energy Partners, would press the dispute.
Read MoreWhere Big Oil is cutting back
Tuesday's back-and-forth highlights a suspected fissure between McClendon and Energy & Minerals Group founder John Raymond—whose company has put at least $3 billion into AEP ventures.
Publicly traded bonds linked to AEP subsidiaries have traded at deep discounts this year. Bonds tied to the Marcellus shale, which were issued by a sister company to American Energy-Utica traded at 75 to 86 cents on the dollar Tuesday, according to a trader. In recent months, Energy & Minerals Group has put roughly $300 million more into its Appalachian operations, which include the Utica efforts, according to someone familiar with the matter.
Raymond, who told CNBC in December that he was accustomed to oil-market volatility and could foresee making money even at $50-per-barrel prices, declined to discuss the settlement details.
Read MoreIs Carl Icahn in too deep with Chesapeake Energy?
McClendon has contended that the Chesapeake suit has chilled the Utica entity's attempts to raise money. Whether that's the case is not clear. Investors have been leery of certain energy investments as crude and gas prices have languished in recently months, but at $7.8 billion, equity issuance among U.S. exploration and development companies reached a record high in the first quarter, according to Dealogic. Debt issuance by energy companies was solid as well.
Nonetheless, the Chesapeake litigation does appear to have cast investor doubts upon the well-being of McClendon's American Energy Partners.
Earlier this year, Citigroup backed out of a planned capital raising plan for AEP after the Chesapeake litigation was filed, and other underwriters and investors have said they'd likely hold off on further exposure to AEP's projects until the legal and financial picture became clearer.