LOS ANGELES — Prosecutors who have charged Alec Baldwin with involuntary manslaughter over a fatal shooting on a movie set dropped a so-called “firearm enhancement” that carried a potential five-year sentence, officials said Monday.

The US actor was holding a Colt .45 during rehearsals for low-budget Western “Rust” in October 2021 when it discharged, killing cinematographer Halyna Hutchins and wounding the film’s director, Joel Souza.

The weapon was only supposed to contain blank bullets.

Baldwin has been charged in the southwest state of New Mexico for manslaughter and faces an 18-month prison sentence, as does the film’s armorer Hannah Gutierrez-Reed.

The prosecutor’s spokesperson said the charge enhancement had been dropped to “avoid further litigious distractions by Mr. Baldwin and his attorneys.”

“The prosecution’s priority is securing justice, not securing billable hours for big-city attorneys,” the statement added.

The move came just days after Baldwin’s team accused prosecutors of committing “an unconstitutional and elementary error,” noting that the the firearm enhancement law was not in on New Mexico’s books at the time of the incident.

The lawyers’ filing said there was a firearm enhancement law in October 2021, but it required that the weapon be “brandished” — displayed in a deliberately intimidating fashion.

A hearing for both defendants is scheduled for February 24, although neither is expected to appear in person.

Assistant director Dave Halls, who handed Baldwin the weapon and told him it was “cold” — industry speak for safe — has agreed to plead guilty to negligent use of a deadly weapon.

He will serve a suspended sentence and six months of probation, prosecutors have said.

Baldwin is also facing civil proceedings, including from Hutchins’ parents and sister, all of whom live in Ukraine.

A lawsuit was lodged on their behalf in Los Angeles earlier this month, seeking unspecified damages from the “30 Rock” star, as well as from a host of others involved in the film.

Baldwin, 64, and other producers of “Rust” have already reached a financial settlement with Hutchins’ widower Matthew.