Hazleton Laboratories Corp. has acquired the animal and molecular toxicology units of Litton Bionetics from Litton Industries Inc. for an undisclosed amount.

Hazleton, based in Vienna, provides biological and chemical research services, manufactures laboratory and medical products, and is a major supplier of research animals. Litton Bionetics, based in Kensington, provides biomedical research and testing services and sells diagnostic products.

Litton Industries said recently that it had agreed to sell 50 percent of its Bionetics subsidiary to a Dutch company, Akzo N.V., and 25 percent to MetPath Inc., a subsidiary of Corning Glass Works. Hazleton said last week that it has agreed to buy the remaining 25 percent by leasing the facilities and paying cash for the assets, with the sale to be completed by Sept. 1.

Bionetics's toxicology units conduct tests of new substances for manufacturers that plan to use them in food, pharmaceuticals and cosmetics. The Food and Drug Administration requires such substances undergo tests to determine whether they have toxic effects, cause cancer or genetic mutations or have other dangerous properties. Both Litton Bionetics and Hazleton test effects of substances on laboratory animals.

The toxicology units employ about 200 workers and together generate annual sales of about $10 million.

Hazleton recently reported earnings of $2.2. million on sales of $55.9 million for its fiscal year, ended June 30.