American University president Joseph J. Sisco yesterday was elected to the board of directors of Government Employees Insurance Co., an appointment approved by D.C. Insurance Superintendent Maximilian Wallach as part of a consent agreement between the auto insurance firm and the Securities and Exchange Commission.

In separate developments, two affiliates of Geico yesterday announced increased dividends for common stock-holders. Government Employees Life Insurance Co. raised its annual dividend to 36 cents a share from 32 cents and Government Employees Financial Corp. increased its quarterly cash payout to 15 cents a share from 12 cents.

As part of a settlement with the SEC last year, following an investigation by the regulatory agency into accounting practices by previous management. Gieco agreed to select a new outside director who would be approved prior to such designation by Wallach.

Geico selected Sisco, who was Under Secretary of State for political affairs before becoming president of American University last July. A State Department veteran, Sisco was a principal adviser on Middle East issues and he rose to the department's top post for career officers.

A native of Illinois, Sisco is married to Jean Head Sisco, a member of the boards of directors at a half dozen major local and national corporations.

At Gieco, a board vacancy was created with the resignation last Sept. 7 of former company chairman Norman L. Gidden, who headed the insurance firm when its growing financial problems became public knowledge about a year ago.

With the increased dividend rate at Government Employees Life, the new quarterly payout of 9 cents will begin with a distribution on March 29 to stock holders of record March 4.

Government Employees Financial Corp.'s new 15-cent payout starts with a quarterly distribution no Feb. 4 to stockholders of record Jan. 24.