OTSEGO, Mich. (AP) _ Two women have been charged with lining up their six children in the home they shared and allowing men to take their pick for sex, police said.

Annette Sanford, 34, of South Haven, was charged last week with four counts of first-degree criminal sexual conduct. Carolyn Wilson, 42, of Bangor, was charged with one count of first-degree child abuse and four counts of criminal sexual conduct. They are not accused of sexually abusing the children themselves.

Investigators say they believe at least seven men visited the women's house frequently in 1987 and 1988 to choose their victims from the line-up. They said the children were then sexually assaulted in their bedrooms.

''The kids would just look at each other as if to say 'Oh God, not again,''' Detective Patrick O'Reilly said.

The women have denied the allegations, police said.

The women, who are not related, were living together in Otsego Township, about 30 miles south of Grand Rapids, and each had three children in the house. Sheriff's Lt. Rick Cain said today that the six children have a number of different last names, and authorities have been unable to determine who their biological fathers are. He said the women have been uncooperative in background checks on them or the children.

The children, five girls and one boy, have been living in foster homes since May 1988, after one of the girls came to school with bruises and told school officials of the alleged abuse. Five of the children are 8 to 13 years old; the sixth is a developmentally disabled 18-year-old girl.

After interviewing the girl at school, Cain said he petitioned the Allegan County Probate Court to have the children removed.

Police didn't seek arrest warrants for the women until two weeks ago, when they believed the children were prepared to testify. ''We didn't feel a year ago they were prepared to testify or could testify,'' Cain said.

Police said the line-ups occurred at least once a week for at least a year. The women also allegedly beat the children and forced them to clean floors with toothbrushes and eat dog food, police said.

Authorities were investigating motives for the alleged crimes. ''The assumption would be money or narcotics changed hands,'' Cain said.

There is medical evidence to substantiate the children's claims of sexual abuse, police said. Two of the girls were believed to have been spared, they added.

One man, Robert Sterling of Muskegon, has been charged with second-degree criminal sexual conduct, and police are seeking others.

''They'd select their child and go into a room to have sex. The kids' stories are consistent and corroborate each other,'' Cain said.

The women were being held in the Allegan County jail, Sanford on $10,000 bond and Wilson on $12,500 bond. A hearing is scheduled Tuesday in circuit court.