An Oklahoma City hospital was accused yesterday of allowing two dozen severely handicapped infants to die without surgery under a policy that based treatment decisions in part on the child's mental and physical potential and the financial status of its parents.

Organizations for retarded and disabled people, joined by the American Civil Liberties Union, said they would file a class-action lawsuit by May 31 unless officials at the state-run Oklahoma Children's Memorial Hospital change the policy.

At a news conference yesterday, lawyers for the organizations said the policy was illegal and unconstitutional and that it discriminated against the poor and minorities. It was unclear if the policy remains in effect.

Oklahoma officials denied any wrongdoing and called the allegations "irresponsible."

The policy became widely known after it was mentioned in a 1983 magazine article published by the American Academy of Pediatrics, according to James Bopp Jr., head of the National Legal Center for the Medically Dependent and Disabled.

The article, written by the Oklahoma physicians involved, described a 1977-82 experiment involving 69 infants born with spina bifida, a condition in which the spine is not closed at birth, and other birth defects.

Of the 69 babies, 36 were given extensive treatment and surgery, and all lived. Twenty-four other babies were denied surgery, and all died within about six months.

In a letter sent yesterday to state and hospital officials, the groups cited a portion of the 1983 article in which the doctors said they had been "influenced by a formulation of the quality of life. In this formula, QL = NE x (H + S)."

That is, it explained, the quality of life is determined by multiplying the infant's physical and mental condition by the anticipated "contribution from home and family and . . . the contribution from society."

The letter said the formula means that the hospital team factors into its life-and-death decisions such political and fiscal matters as reduced government spending for medical care and "geographical and financial limitations."

"Depending on the team's assessment of the 'contributions' from home and society," the letter said, "one child may be recommended for life-saving surgery while another, with identical physical prognosis, may be recommended for death.

"Membership in a racial minority counts against having a high enough 'quality of life' under your criteria. A person who is black is less likely to be recommended for treatment than a person who is white."