BANGOR – The son of a Patten man serving an 11-year prison term on sex charges was sentenced Friday in Penobscot County Superior Court to serve nine months in jail on similar charges.

Just before sentencing, Kirby G. Williams Jr., 30, pleaded guilty to sexual abuse of a minor in May 2005. He was sentenced to four years in prison with all but nine months suspended and two years of probation.

Both men will be required to take part in sex offender counseling and register as convicted sex offenders after they are released.

The victim of the younger man was a female relative who was 15 years old when he sexually abused her, according to Michael Roberts, deputy district attorney for Penobscot County.

Neither Williams nor the victim, who attended the hearing, addressed the court at Friday’s sentencing.

The defendant’s father, Kirby G. Williams Sr., 54, of Patten also was charged with sexually abusing the same girl. Those charges were dropped after the elder man was convicted in January by a Penobscot County jury of sexually abusing a different female family member.

Neither the father nor his son pleaded guilty to having sexual contact with the same victim at the same time. Roberts said that although the younger Williams did not testify against his father, he provided prosecutors with information that helped them convict the older man.

“The sentence is reasonable, given the defendant’s cooperation,” Superior Court Justice William Brodrick said Friday in accepting the sentence outlined in a plea agreement. “The act is truly worth more than nine months because it actually is a form of rape.”