The Supreme Court Monday agreed to study the rights of unwed fathers whose children are put up for adoption by their mothers.

At issue: whether unwed fathers who actively seek custody of their children may be stripped of all parental rights if adoption is deemed to be in the children's best interest.The justices said they will use a case from San Diego, Calif., to review rulings that terminated Edward McNamara's parental rights to his daughter, Katie, who is now 6 years old.

McNamara and Katie's mother, unidentified in court records, had not seen each other for eight months when Katie was born in 1981. McNamara did not learn of the pregnancy or birth until he was told Katie, then a month old, had been placed in a foster home awaiting adoption. He quickly sought custody.

Katie was 5 months old before a trial was held on McNamara's custody request, and a California judge ruled that it was in Katie's best interest to stay with the foster parents she had been living with.

In other action the court:

Agreed to decide whether states may bar political party leaders from endorsing primary election candidates and whether states may regulate political party structure.

Refused to let a Dallas blood bank withhold the names and medical records of its donors from a woman who says her husband contracted AIDS after receiving transfusions.

Left intact a key federal regulation designed to foster competition within the natural gas industry.

Rejected an appeal by U.S. District Judge Alcee Hastings, who says he unlawfully is being subjected to possible impeachment.

Refused to let the government approve the use in cosmetics of color additives that pose a minimal risk of causing cancer.

Let stand a ruling that a worker may not be fired for refusing on religious grounds to pay union dues.

Said it will decide whether public criminal records compiled by the FBI generally must be released under the Freedom of Information Act.

Agreed to decide whether payments, called "fixed donations," made to the Church of Scientology by its members may be claimed as federal income tax deductions.