Milk that can be stored for months without refrigeration will be available in some Washington area supermarkets beginning May 1, industry officials said yesterday.

The unopened containers can be kept at room temperature up to three months because of an ultra-high temperature process that kills bacteria and heat-resistant spores. Special sterilized packages protect the product from bacteria, air and light. Once opened, refrigeration is required, although spoilage is slightly slower than with regular pasteurized milk.

Dairymen Inc., a milk farmers' cooperative, will be marketing white milk in quart and half-pint containers under the name Farm Best and in flavored half-pints called Sip Ups. The cooperative is owned by 8,000 dairy farmers in 17 eastern and southeastern states, including Maryland and Virginia.

The special milk will be available as whole white milk, low-fat white milk and low-fat chocolate milk. Sip Ups will come in banana, vanilla, strawberry, fruit and chocolate flavor.

A quart of white whole milk is expected to cost 89 to 99 cents, compared to 61 cents for a quart of regular whole milk at many supermarkets. The Sip Ups will sell for 99 cents for a three-pack.

Dairymen officials said major food chains would carry the new milk, which is produced in Savannah, Ga. Richard McCready, president of RMI and Associates, a Baltimore food brokerage firm handling the marketing of the milk here, said A&P stores have ordered the product for their local stores.

McCready also said he expects Giant supermarket to carry the product. However, a Giant representative said late yesterday that the chain hasn't made a final decision.

Safeway officials said they will not carry the new milk at this time.