An Alexandria judge agreed yesterday to the early release of a man who had been sentenced to a year in jail after pleading guilty to the statutory rape of his two stepdaughters when they were 14 years old.

The 54-year-old man will be released from jail Dec. 15 after serving four months of a one-year sentence. He then will be required to complete a 90-day alcohol rehabilitation program that includes a three-week stay at a farm in Fauquier County, followed by a stay at a residential home in Arlington.

After that, the man will be free to return to his job at a Northern Virginia printing company, which has asked him to return to work.

The decision by Circuit Court Judge Donald M. Haddock, which was opposed by a city prosecutor, came at the urging of defense attorney J. Ronald Lynch, who argued that the man needs extra help to overcome alcoholism. A statement submitted to the court by Dr. Lawrence Peters of Circle Terrace Hospital in Alexandria said the man "has not been sober for the last 30 years."

The early release was opposed by Assistant Commonwealth's Attorney Constance Frogale, who said she was "not satisfied" by the judge's decision. The man "was not being punished for being an alcoholic; he was being punished for being a sex offender," she said.

The rapes occurred between 1972 and 1974, but the stepdaughters, now 24 and 27, did not press charges until last August. The older woman said the man fathered her 10-year-old daughter.

Frogale said she had hoped the man would serve the full one-year jail sentence called for in a plea bargaining agreement reached last August, especially since he was receiving treatment for alcoholism in jail. The maximum penalty for statutory rape -- sexual relations with a person under the age of 18 -- is 20 years in prison.

The judge specified that the suspension of sentence will be revoked if the man has any contact with his family during his five-year probation.

The man's employer, who has asked him to return to work at the beginning of next year, said he saw no reason he should not rehire him, adding: "He has been an excellent employe for the past 20 years."