BARTLESVILLE, Okla. (AP) _ The board of directors of Phillips Petroleum Co. elected C.J. Silas and Glenn A. Cox to top management positions with the oil company Tuesday.

Silas, the company president, was elected chairman and chief executive officer, succeeding William Douce. Cox, an executive vice president and chief financial officer, was named president and chief operating officer.

The action at company headquarters in Bartlesville was a formality. The board had announced Feb. 12 that Silas would replace Douce, who is retiring effective April 30, and that Cox would move up to Silas' old position. The two were unanimous choices Tuesday.

Silas and Cox will assume their new duties May 1, a day after the annual shareholders meeting.

Silas, 52, joined Phillips in 1952. He is a chemical engineer who first gained renown at Phillips as a standout on the Phillips 66ers basketball team. He played on the U.S. team that won the Pan American games in 1955.

In 1980, Silas was elected executive vice president of the company. Before that, Silas was senior vice president in charge of worldwide exploration and production, gas and gas liquids and certain administrative functions. He also has been involved in chemical sales in Europe and Africa.

Cox became executive vice president in 1980 and has been responsible for the corporate financial matters. He joined Phillips after graduating from Southern Methodist University and serving 41/2 years as a pilot in the U.S. Air Force.

Since 1962, Cox has been a member of the Phillips board and its executive committee. Previously, Cox was vice president for management information and control and was assistant to the chairman of the company's operating committee.

Douce, who turned 65 in December, joined Phillips in 1942 after graduating from the University of Kansas with a chemical engineering degree. He became chief executive officer in 1980 and chairman in 1982 following the retirement of William Martin.

Douce was to have stepped down Jan. 1 but stayed on at the request of the company's board of directors. In the past few months, Phillips has been the target of two hostile takeover attempts.

Phillips also raised its quarterly dividend on common stock to 75 cents from 60 cents and set May 30 as the record date for its previously proposed 3- for-1 stock split in the form of a 200 percent stock dividend.

The action is subject to stockholder approval.

The Phillips board also declared a dividend in the form of preferred shares having a market value on a fully distributed basis of $300 million payable to common holders of record on May 30.