The sudden resignation apparently stems from a dispute Mr. Levy had with the board of directors about the progress of Activision's turnaround effort.
He said his resignation stemmed from concerns expressed by volunteers in his petition drive.
The resignations of top editors at The Christian Science Monitor stemmed as much from religious conviction as from concern about journalistic standards.
Analysts had speculated that Mr. Schofield's resignation stemmed in part from his inability to gain concessions from the unions.
Bertelsmann's chairman and chief executive, Thomas Middelhoff, said yesterday that the resignations stemmed entirely from a reorganization of the company's music division.
Mr. Fromstein confirmed that his resignation stemmed from "two people with different ideas about where a company should be going."
Sources at Dean Witter said the resignations stemmed from last month's reorganization of the taxable fixed-income unit.
Several publishing executives said her resignation had stemmed from a perceived lack of management control and her free-spending ways on new books.
Grantham, in a telephone interview, denied that his resignation stemmed from anything other than the reason given last Friday.
His resignation stemmed from his most recent brush with the law.