The payment, to end charges filed by the Securities and Exchange Commission, is the largest yet to be levied on an auditing firm in the aftermath of the accounting scandals of the last decade. The money will be deposited into a fund to compensate people who lost money when the cable-system operator collapsed.

"When auditors turn a blind eye toward misconduct on a high-risk client and allow a fraud of this magnitude to go undetected, the consequences will be severe," said Mark Schonfeld, director of the SEC's Northeast regional office.

Deloitte & Touche was accused of improper professional conduct by failing to detect fraud when it reviewed Adelphia's books for the 2000 fiscal year. The cable company, based in Greenwood Village, Colo., filed for bankruptcy protection in 2002 after revelations that the controlling Rigas family had borrowed close to $2.3 billion using Adelphia's credit.

Adelphia and members of the Rigas family on Monday agreed to settle separate charges stemming from the fraud. Company founder John Rigas and his son, Timothy, were convicted of conspiracy, bank fraud and securities fraud last year.

Deloitte & Touche separately agreed to pay $375,000 to settle charges that it failed to stop accounting fraud at Just for Feet Inc. in its 1998 audit of the sports retailer, before the company filed for bankruptcy. Steven Barry, the engagement partner on the audit, agreed to a ban of at least two years from practicing as an auditor before the SEC, and Karen Baker, the audit manager, agreed to a ban of at least one year.

Deloitte & Touche agreed to both settlements without admitting or denying wrongdoing. It blamed Adelphia and Just for Feet for deliberately misleading auditors.

"These cases raise a larger issue facing the auditing profession," said James Quigley, CEO of Deloitte & Touche. "Among our most significant challenges is the early detection of fraud, particularly when the client, its management and others collude specifically to deceive a company's external auditors."

Under the settlement, Deloitte & Touche agreed to fortify a risk-management program that was already in place when it conducted the audit of Adelphia. Among the changes is an agreement to appoint knowledgeable partners to oversee the planning and design of audit procedures for any company in its risk-management program.

Penalties against auditing firms have increased with each settlement. Last week, KPMG LLP agreed to pay $22.5 million to settle charges that it failed to stop a massive accounting fraud at Xerox Corp., and in October agreed to make a $10 million payment to compensate investors who lost money in a fraud involving Gemstar-TV Guide International Inc.

Helene Glotzer, an SEC enforcement attorney, said that the agency's investigation in connection with Deloitte & Touche's audit of Adelphia's financial records was continuing.

Attorneys for the two Deloitte & Touche auditors who reviewed the financial statements of Just for Feet did not return phone calls.

Based in New York, Deloitte & Touche is the U.S. arm of Deloitte Touche Tohmatsu, a Big Four accounting firm and consulting company.