A former Boy Scout leader pleaded guilty in Fairfax County Circuit Court yesterday to five counts of sodomy and aggravated sexual battery involving three members of his Reston troop.

Carlton L. Bittenbender, 41, formerly employed by the American Newspaper Publishers Association, said in a clear voice that he was guilty on each of the five felony counts. He faces a maximum sentence of life in prison plus 80 years, prosecutors said.

Judge J. Howe Brown Jr. set sentencing for Jan. 10, after Bittenbender has undergone evaluation and treatment at a special sexual-disorder clinic at Johns Hopkins Hospital at his own expense.

Assistant Commonwealth's Attorney Melinda S. Norton, who prosecuted the case, said she was pleased with the pleas. "I prefer to save the children from having to testify," she said.

Defense attorney Gregory D. Haight said that his client, who was convicted in Rhode Island on similiar charges about four years ago, was in need of help because of "his disease." He described Bittenbender as a pedophile, an individual whose sexual preference is children.

"These kinds of people are generally upstanding citizens," Haight said. "If you could take away this problem, you would find a marvelous human being."

Bittenbender was placed on probation about four years ago in Barrington, R.I., where he was a scout leader, the lawyer said. Bittenbender had pleaded no contest to the charges there and was ordered to get psychiatric help, Haight said.

While it could not be learned yesterday if he remains under probation in Rhode Island, Haight said Bittenbender had received psychiatric help since his initial conviction.

Haight said the Johns Hopkins program, which uses the controversial drug Depo-Provera to change hormonal balance and lower sex drive, has had "remarkable success."

The Rev. Douglas Ibach, pastor of the United Christian Parish, which sponsored Troop No. 1970 that Bittenbender led for about a year and a half, said, "In many ways he was a really tremendous guy. It's really sad. I agree with his attorney."

Ibach said the local troop committee, which has been in the process of conducting "damage control" since Bittenbender's Aug. 22 arrest, has invited parents to meetings to discuss what happened and talk about safeguards. "The people have been very fair-minded, no one has condemned anybody," he said.

Bittenbender, who was a field adviser for the newspaper education program at the newspaper association's officies in Reston, was charged with four counts of aggravated sexual battery with a child under the age of 13 and one count of sodomy with a child under the age of 13 in the five incidents involving the three children from September 1984 to February. Since his arrest, Bittenbender has been held in the county jail in lieu of $125,000 bond.