GREENVILLE, S.C. (AP) - A bill by state Sen. Mike Fair would change South Carolina's adoption law to bar unmarried couples from becoming foster parents or adopting children in the state's care.

Fair, R-Greenville, has tried unsuccessfully in past years to bar homosexuals from eligibility to adopt children in the custody of the state Department of Social Services.

He said monogamy in a relationship outside of marriage often doesn't last long and thinks such living arrangements are unhealthy for children.

Some children's advocates say Fair's proposal could reduce the number of available homes.

The changes wouldn't apply to private adoptions, Fair said.

He is pressing the issue as courts across the nation weigh arguments on the rights of homosexuals as adoptive parents. The 11th Circuit Court of Appeals decided Thursday to uphold a Florida law that prohibits gay people from adopting.

Virginia Williamson, general counsel for South Carolina's Department of Social Services, said the agency does criminal and child abuse background checks on people who want to adopt children but doesn't have a policy ruling out unmarried couples.