Archibald Cox Jr. is resigning as president...

Archibald Cox Jr. is resigning as president and chief executive of the investment firm First Boston Corp., effective Sept. 1. He is the son of Archibald Cox, the late Watergate special prosecutor.

The younger Cox’s resignation comes about a month after CS First Boston Group, the firm’s Swiss-based parent, reorganized its worldwide operations into a single firm to end strife between its regional divisions.

CS First Boston said its chief executive, John Hennessy, will assume Cox’s duties temporarily.

Bear Stearns Cos. announced the appointment of president James E. Cayne to the additional title of chief executive.

Chairman Alan C. Greenberg will continue devoting his full time to duties as senior leader of the company, according to a company statement.

Bear Stearns Cos. is the parent of Bear Stearns & Co., one of Wall Street’s leading investment banking companies, with more than $3.3 billion in capital.

Martin Dunn was named editor in chief of the Daily News in New York, effective Aug. 1. Dunn had been editor in chief at the Boston Herald since March.

Dunn will be replaced in Boston by Alan Eisner, the Herald’s current managing editor, said Frank Dyer, the Herald’s assistant to the editor.

Michael L. Durik has been named senior vice president of human resources and administration of Mattel Inc.

Durik, 44, was previously executive vice president of administration for the Limited Stores division of Limited Inc.