NEW YORK (CNN/Money) - Three former Rite Aid executives and a current manager Friday were hit with federal criminal charges involving securities and accounting fraud that allegedly forced the drugstore chain to restate more than $1 billion in earnings.

The U.S. attorney for the Middle District of Pennsylvania charged former Rite Aid CEO Martin Grass, former Chief Financial Officer Frank Bergonzi and former Vice Chairman Franklin Brown with "conducting a wide-ranging accounting fraud scheme."

The charges include conspiracy to defraud, fraud in connection with the purchase or sale of securities and making false statements to the Securities and Exchange Commission. Grass and Brown also are accused of tampering with witnesses and obstructing various investigations

Eric Sorkin, currently executive vice president for Pharmacy Services, was charged with conspiracy to obstruct justice and making false declarations to a grand jury. He was suspended by Rite Aid Friday morning.

The U.S. Attorney for the Middle District of Pennsylvania alleges the executives colluded in overstating Rite Aid's income in every quarter from May 1997 to May 1999, forcing the company to restate results by $1.6 billion, the largest restatement ever recorded, according to the SEC.

"The charges announced today reveal a disturbing picture of dishonesty and misconduct at the highest levels of a major corporation," said Wayne Carlin, regional director of the SEC's Northeast regional office. "Rite Aid's former senior management employed an extensive bag of tricks to manipulate the company's reported earnings and defraud its investors."

The Associated Press said that telephone messages left at the homes of Grass, Brown and Bergonzi were not immediately returned. Sorkin hung up on a reporter who reached him at home, the AP reported.

The four men were not arrested and have not entered pleas. They will be summoned to appear in federal court in the coming weeks

Karen Rugen, a Rite Aid spokeswoman, said that the company has "changed the way we do business, include strengthening our financial controls."

"We're a very different company and a much stronger company than we were two years ago," Rugen said.

Separately, Rite Aid said Friday it reached a settlement with the SEC over an investigation into its former management's financial reporting and accounting practices.

Rite Aid said it will pay no fine under the settlement and it neither admitted nor denied any of the findings in the SEC's order but entered a cease and desist order closing the SEC investigation.

Rite Aid said the accounting issues identified in the order were addressed in the restatements of the company's financial statements in 2000 and that the company cooperated fully with the agency's investigation, as it will with any further probes.

"Our new management team has changed the way Rite Aid does business, including strengthening our internal financial controls and maintaining the proper records to file accurate financial reports with the SEC," CEO Bob Miller said in a written statement.

In November 2000, Rite Aid agreed to pay $45 million in cash plus about $150 million in senior secured notes to its shareholders to settle a class-action suit accusing the drugstore chain of releasing misleading information that artificially inflated share value. A federal judge approved the deal last year.  

-- The Associated Press contributed to this report