HARRISBURG — Pennsylvania Gov. Ed Rendell plans to commute the life sentences of three men convicted of murder who have served decades behind bars, his office said Wednesday.

Rendell spokesman Gary Tuma said the governor today will sign clemency orders for inmates Keith O. Smith, William Fultz and Tyrone Werts, each convicted of separate slayings in Philadelphia in the 1970s.

A Corrections Department spokeswoman said it was not clear how soon the men would be released to halfway houses, where they will go before being released on parole.

Tuma said Rendell’s decisions were influenced by several factors: the men’s role as accomplices rather than triggermen in the slayings, their incarceration of many years, the lighter sentences for others involved in the killings, and the unanimous clemency recommendation from the state Pardons Board.

Tuma said Rendell will impose conditions that if the men are convicted of a criminal offense or violate parole, the commutation may be revoked by the governor upon the recommendation of the Pardons Board and after a public hearing.

William DiMascio, executive director of the Pennsylvania Prison Society prisoner advocacy group, knows all three and described them as good candidates for release.

The 4-0 votes by the Pardons Board earlier this month — Attorney General Tom Corbett, the governor-elect, was absent — were the first such votes in more than six years.