CINCINNATI (AP) _ The Procter & Gamble Co. said Tuesday it is forming a joint venture to do business in Venezuela with a Venezuelan manufacturer of disposable diapers and other infant care products.

Procter & Gamble said the joint venture with Industrias Mammi, C.A., of Caracas, Venezuela, is subject to approval by the Venezuelan government. P&G, a Cincinnati-based company which makes and sells food and personal-care products worldwide, declined to reveal terms of the agreement.

Mammi makes and markets disposable diapers, other baby care items and feminine protection products. It employs about 500 people and owns and operates a manufacturing facility near Caracas.

Procter & Gamble de Venezuela, C.A., is based in Caracas and has operated since 1950. It has plants in Caracas and Barquisimeto that together employ about 1,000 people. P&G's Venezuelan subsidiary makes and sells detergent, bar soap, toothpaste, dishwashing liquid and shampoo products.

Procter & Gamble had worldwide sales of $19.3 billion in fiscal 1987-88. About one-third of that total was overseas sales. The company sells products in more than 140 countries.