A court suit brought by the Roman Catholic Sisters of the Most Precious Blood has brought a victory of sorts in the running battle between drug manufacturers and church groups over the promotion of infant formula in Third World countries.

Bristol Myers, manufacturers of ENFAMIL, agreed to mail to all its stockholders at the company's expense an 11-page statement that includes both the religious order's grim accounts of experience with view of the problem, including some grim accounts of experience with the formula in poor countries, and a company statement of policy for promotion of its product in under-developed areas.

The company's action represents one of the conditions agreed to in an out-of-court settlement of the suit, which was filed two years ago in federal court in New York.

Another condition was fulfilled on Monday when the Bristol Myers board of directors met with representatives of the church group to discuss problems the religious leaders believe are raised by the infant formula promotion in poor lands.

Church groups have assailed for years the promotion by drug and food manufacturers of infant formula in Third World countries. They carge that advertising promotion for such products play on the naivete of uneducated women to try to convence them the manufactured product is superior to mother's milk.

Irrespective of the merits of the product itself, the church groups also maintain, sanitary conditions in developing countries make the use of the formual hazardous.

The dry formula must be mixed with water. Facilities to sterilize both the water for the formula and the required bottles and nipples often are lacking. So is the refrigeration required for storage of the formula.

In their statement, the church group cites a Pan American Health Organization study of death from diarrhea among infants one to five months old in Jamaica.

According to this study, twice as many deaths occurred in the formula-fed babies as among breast-fed infants.

The religious groups also maintain that the cost of the infant formula can absorb "from 10 to 50 percent of the weekly disposable income of a family" in a underdeveloped areas.

Church groups and others have been trying for years, largely through stockholders' resolutions, to persuade the manufacturers to curtail distribution of infant formulas in the Third world. When this tactic brought no results, the Precious Blood Sisters, who own 1,000 shares of Bristol Myers stock, brought the court suit.

The sisters acted through the New York-based Interfaith Center on Corporate Responsibility, an inter-religious cooperative over social issues.

In its statement, Bristol Myers acknowledges that "mother's milk is ideal for infant nutrition in normal circumstances," and promises that "formula product labels will state 'Breast milk is best for your infant and is the preferred whenever possible.'"

Briston Myers stated that company policy "does not permit the advertising of infant formulas to consumers in underdeveloped or developing countries" and also prohibits giving free samples directly to mothers in such countries.

But the company will continue "limited distribution" of samples to doctors and to hospitals, "for dstribution to mothers at the hospitals discretion," the policy statement says. Church groups object to such distribution, maintaining that for a hospital or a doctor to give a mother a product carries an implied recommendation for its use.