Charles M. Wantland, the convicted killer of 12-year-old Donald Alan Henley, was sentenced to two consecutive life terms in prison yesterday in Prince George's County Circuit Court.

Those penalties, and a three-year term Wantland also received for carrying a deadly weapon, were the maximum sentences possible for his conviction last July on charges of premeditated murder and a first-degree sexual offense.

Wantland, 44, will not be eligible for parole for 25 years, a spokesman ofr the state's attorney's office, which prosecuted the case, said.

Wantland was not sentenced under Maryland's new death penalty law because the murder of Donald Henley occurred on July 17, 1978, two weeks before the law took effect.

Joseph Niland, the public defender representing Wantland, said yesterday he expects the case to be appealed to the state Court of Special Appeals within 30 days.

Blond-haired "Donnie" Henley was found stabbed to death a few blocks from his Clinton home and the Berger Mansion, an historic though dilapidated home where Wantland was living and working as part of a federally funded and county supervised job training program.

Wantland had been paroled three weeks earlier from a state correctional institution where he was serving a sentence for second-degree murder.

The Henley family recently filed a $48 million lawsuit against Prince George's and the local contractor running the job training program, charging them with negligence in hiring Wantland and locating the program in their neighborhood.