* Dow Chemical Co. announced the retirement...

* Dow Chemical Co. announced the retirement of its chairman, Paul E. Oreffice, and at the same time named Frank Popoff as his replacement.

Oreffice will retire Dec. 1, the firm, based in Midland, Mich., said in a statement.

Popoff is now president and chief executive and will retain all those duties until April 1, 1993, when the president of Dow U.S.A., William S. Stavropoulos, assumes the duties of president and chief operating officer of the company.

Stavropoulos will report to Popoff, who then will become CEO and board chairman.

Oreffice joined the company in 1953. He was named president and CEO in 1978, and chairman in 1986. His retirement comes at the company’s mandatory retirement age of 65 for inside directors.