By Anna Driver and Brian Grow

Feb 20 (Reuters) - Chesapeake Energy Corp said on Wednesday its internal investigation of the financial dealings of outgoing chief executive Aubrey McClendon found no "intentional" wrongdoing, but authorities and analysts said the issue was far from over.

The company's statement also said a review by its board of directors found Chesapeake "did not violate antitrust laws" as it acquired oil and gas rights in Michigan in 2010.

The company did not say how it reached its conclusions and did not release a full report of its investigation, and state and federal investigations of the company continue.

The U.S. Securities and Exchange Commission is examining McClendon's financial transactions, while the Department of Justice and the attorney general in Michigan are investigating whether Chesapeake violated antitrust laws.

"The importance of independent - rather than internal - investigations cannot be emphasized enough in a case involving antitrust bid-rigging allegations," said a spokeswoman for Michigan Attorney General Bill Schuette. "Our thorough, independent investigation into these serious allegations will continue."

A series of Reuters investigations last year triggered civil and criminal probes into the second-largest U.S. producer of natural gas. Big shareholders Carl Icahn and Southeastern Asset Management took control of the board in June after McClendon was stripped of the chairmanship of the company he co-founded in 1989.

"A finding of 'no intentional misconduct' still does not mean there was no misconduct," said Mark Hanson, an oil and gas analyst at Morningstar Inc in Chicago. "I think just the appearance of impropriety should be avoided and I think that certainly wasn't the case for either McClendon or the former board."

A U.S. Justice Department spokeswoman confirmed late on Wednesday that the department's Antitrust Division still had an open investigation into "the possibility of anticompetitive practices in the purchase and lease of oil and gas properties."

Charles Elson, director of the Weinberg Center for Corporate Governance at the University of Delaware said the company still faces shareholder litigation as well as government probes.

"Board investigations are only part of the process. I would not say this is the final word," said Elson.

Last month, Chesapeake said McClendon was stepping down as CEO. McClendon cited philosophical differences with the board as the reason for his departure. He will leave on April 1.

As the board tried to rein in capital spending and salary, McClendon resisted, a situation that created tension and eventually ended in the executive's departure, according to a source familiar with the board.

"I don't think that any of this was done intentionally to harm the company or shareholders," the source said. "There's probably an error in judgment that a lot of CEOs have."

Last June, Reuters reported that Chesapeake plotted with Encana Corp, its top competitor, to suppress land prices in the Collingwood shale formation in northern Michigan.

A Reuters investigation last April found McClendon arranged to personally borrow more than $1 billion from EIG Global Energy Partners, a firm that is a big investor in Chesapeake.

The loans, arranged through McClendon's personal shell companies, were secured by his interest in Chesapeake wells. Under the controversial Founders Well Participation Program (FWPP), McClendon is allowed to take up to a 2.5 percent stake in every well Chesapeake drills. The board has since set a termination date of June 2014 for the FWPP.

The Chesapeake probe was led by director V. Burns Hargis, president of Oklahoma State University and former vice chairman of Bank of Oklahoma and BOK Financial from 1997 to 2008.

More than 70 percent of Chesapeake shareholders voted to remove Hargis as a director at the company's annual meeting in June. The vote was non-binding and Chesapeake elected to keep him on pending completion of the investigation of McClendon.

It is unclear whether Hargis will step down now. His spokesman declined to comment.

The Chesapeake board did not disclose the total number of transactions included in its investigation, nor the names of the companies involved.

More than a million pages of documents were collected and reviewed and more than 50 interviews conducted, the company said, without providing specifics.

The shares of Chesapeake, which is due to report fourth-quarter earnings on Thursday, closed down almost 0.6 percent Wednesday on the New York Stock Exchange. 

(Additional reporting by Joshua Schneyer)

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