A former partner at Latham & Watkins pleaded guilty Friday to defrauding both clients and his own firm by charging them more than $300,000 in personal or false expenses.

Samuel A. Fishman, a mergers and acquisition specialist in Latham's New York office from 1993 to 2005, was designated billing partner for a number of firm clients. According to prosecutors at the Southern District of New York U.S. Attorney's Office, Fishman, 51, used his position to carry out a fraudulent scheme over the course of several years.

Responsible for supervising and approving invoices sent to clients, Fishman added to the bills a number of inappropriate items, mischaracterizing them as charges for photocopying or express mail. He also fraudulently sought reimbursement from his firm for a number of personal expenses he claimed were for business.

The U.S. Attorney's Office did not identify Latham as Fishman's firm in a criminal information filed with the guilty plea, nor was the firm's name mentioned in court Friday afternoon when Fishman entered his plea to one count of mail fraud. But in a statement Friday, the firm acknowledged Fishman as a former partner and said his misconduct had come to light in 2005.

Latham "immediately acted to protect our clients fully, and disclosed the matter to appropriate law enforcement authorities," said David Gordon, Latham's New York managing partner. "Mr. Fishman resigned from the firm at the time the issues were discovered. Since that time, we have cooperated fully with the investigation."

In announcing Fishman's guilty plea, prosecutors noted that the firm had reimbursed its clients hundreds of thousands of dollars that had been fraudulently charged. A firm spokesman Friday declined to identify the clients defrauded by Fishman.

The criminal information said Fishman's clients were in the banking, utilities, telecommunications and entertainment industries. He has previously acted as lead counsel for companies including movie theater chain AMC Entertainment Inc. and JPMorgan Partners, the private equity arm of JPMorgan Chase & Co.

Accompanied at Friday's hearing by defense lawyer Jack Litman of Litman, Asche & Goiella, Fishman expressed remorse to Southern District Judge Victor Marrero.

"I am very sorry for what I did," he told the judge.

Fishman's sentencing is scheduled for June 27. The mail fraud charge carries a maximum sentence of 20 years in prison. Fishman also has agreed to forfeit $350,000 in ill-gotten wealth. He also faces likely disbarment.

A number of major firms have had to deal in recent years with fraud by partners, though most instances have resulted in disbarment or other disciplinary sanction as opposed to criminal prosecution.

In 2006, former WilmerHale intellectual property partner William P. DiSalvatore resigned from the bar after admitting to a litany of misconduct, including falsifying expense reports and assigning associates to perform "pro bono" work for friends and family. He claimed more than $109,000 in false personal expense.

Willkie Farr & Gallagher and the former Kronish Lieb Weiner & Hellman are two other firms that have also terminated partners for fraudulently seeking reimbursement for personal expenses.

In most such cases, including that of Fishman, the defrauded amounts have been small compared to what the perpetrators earn as partners. Last month, Latham said it had profits per partner of $2.3 million in 2007.

Steven Lubet, a legal ethics professor at Northwestern University School of Law, said he always found it "incredible" that highly paid partners would resort to fraud. He said he could only imagine that such people were overspending trying to emulate the lifestyles of those they represented.

"The clients have that kind of money, the lawyers don't," said Lubet. "Sometimes, lawyers decide they want to live like their clients and that extra money has to come from somewhere."

Perhaps the most well-known case of a lawyer bilking his clients and firm was Webster Hubbell, the former associate attorney general under President Bill Clinton.

Hubbell was forced to resign his position in 1994 after his former partners at Arkansas' Rose Law Firm discovered billing irregularities. He later pleaded guilty to fraudulently charging almost $500,000 for personal expenses and legal work never actually performed. He served 16 months in prison.