Antionette Slovik, 64, the widow of Pvt. Eddie Slovik, the only American soldier executed for desertion in World War II, died of cancer Friday at Sinai Hospital in Detroit.

Her death occurred several days before a Senate committee was to begin considering a bill that would have awarded her $72,000. The sum represents the value of her husband's $10,000 GI life insurance policy plus interst.

The death of Pvt. Slovik occurred at 10:05 on the morning of Jan. 31, 1945. He was "shot to death with musketery," in the words of the applicable Army regulations, by men of the 28th Infantry Division, of which he was a member.

In all, 21,049 American soldiers deserted during the war. Forty-nine were sentenced to death. Slovik was the only one executed. He was the only American soldier to die for desertion since the Civil War.

The sentence had been approved by Gen. Dwight D. Eisenhower, who wanted to deter other deserters. But the action never was announced to other troops-- and so it could not act as a deterrent-- and all records pertaining to the case were sealed by the Pentagon for several years afterward.

Six weeks after Slovik had gone before the firing squad in the Vosges Mountains in France and then been interred in an ummarked grave, Mrs. Slovik was told merely that he had died in Europe.

Like her husband, whom she called "Daddy Blue Eyes," Mrs. Slovik was of Polish descent. They were married shortly after he was released from a reform school, where he had been sent for petty crimes. At first, he was classified 4-F. This later was changed and Slovik was drafted early in 1944.He was sent to Europe as an infantry replacement despite the view of the commanding officer of his training company that he was unfit for combat duty.

When Mrs. Slovik applied for the proceeds of her husband's GI insurance, she was told that a clause in the policy forbade payment where death was "inflicted as lawful punishment for a crime."

To protect her husband's name, she pretended to friends that she had been paid.

The story of Eddie Slovik became widely known with the publication in 1954 of a book about it by William Bradford Huie. Five million copies were sold. In 1974, a television movie about the incident was broadcast.

In 1974, with the help of Robert DeFinis, a publicist; Edward P. Woods, who had acted as Slovik's defense counsel at his court-martial, and Bernard Edelson, an attorney, Mrs. Slovik began a new effort to collect on her husband's insurance.

At a hearing before the Army Board for the Correction of Military Records in 1977, Mrs. Slovik wept when a letter written to her by a chaplain who had witnessed the execution was read into the record. The chaplain wrote that Slovik had shown "as great a courage as any soldier I saw go into battle and die."

"Nine years after the execution is when I found out," Mrs. Slovik told the Board for the Correction of Military Records. "All I got from the Army was a telegram that he had died in the European Theater of war and a letter to return the $55 allotment check, which I did. After that, nothing."

President Carter was among those who said they would favor legislation to provide Mrs. Slovik with the benefits. A bill was introduced in the Senate. Sen. Carl Levin (D-Mich.), one of its sponsors, said yeesterday, "The opportunity for the United States government to show compassion to Mrs. Antoinette Slovik died with her this morning."

There were no immediate survivors.