Du Pont has received government approval to market Ethmozine, the first Soviet drug licensed and developed by an American pharmaceutical company. The drug, which is used in the treatment of abnormal and life-threatening heart rhythms, was discovered in the late 1960s in Moscow and has been available in the Soviet Union for about 18 years.

TWA will sell four jets by the end of the month, cut back its flight schedule and end service to seven cities by Oct. 1. The seven cities have not yet been identified, but probably will include Nassau and Freeport in the Bahamas and Syracuse, N.Y.

Gulf States Utilities has agreed to settle its four-year contract dispute with the Southern Co. of Atlanta for an estimated $300 million in cash and GSU stock.

Chrysler's Pentastar subsidiary agreed to buy Dollar Rent A Car, the fourth-largest rental car system, providing a ready market for fleet sales. Ford already owns a share of Hertz and GM a share of National. Terms were not released.

Unisys turned to longtime Japanese partner Mitsui for $200 million in new capital. Mitsui will purchase $150 million in new preferred stock from Unisys and loan $50 million to the company.