Good news for Erik and Lyle Menendez ... the Los Angeles County District Attorney's Office tells us they're open to considering a change in conviction that would set the brothers free at the bang of a gavel.

Here's the deal ... L.A. County D.A. George Gascón has filed legal docs asking Judge William C. Ryan to resentence the Menendez brothers at a November hearing. If that happens, the brothers would be eligible for immediate parole, but that would require an affirmative ruling by the California Parole Board.

TMZ broke the story, we've learned Erik and Lyle's attorney, Mark Geragos, will ask the judge to change their conviction from murder to voluntary manslaughter ... and under a new law, the judge has the power to do so. If that were to happen, Erik and Lyle would be free men, because the maximum sentence is 11 years and they've served 35 years.

The Los Angeles County District Attorney's Office tells TMZ ... "While we currently believe that the evidence supports the first-degree murder charge, we remain open to consider any additional evidence and argument by counsel."

Based on what the D.A.'s office is saying here, it feels like they might well agree to changing Erik and Lyle's conviction to voluntary manslaughter ... and that would be a game-changer.

Another thing that appears to be working in the Menendez brothers' favor ... L.A. County Superior Court Judge Ryan has a reputation for fearlessness and isn't afraid to reverse another judge's ruling when he feels it was wrong.

Sounds like the stars may be aligning here for Erik and Lyle.