New York City Transit is finally moving against perverts who use crowded trains as an opportunity to grope women.

Weeks ago, The Post exclusively reported that agency officials were holding back on an ad campaign against sicko straphangers out of internal fears that it could actually provoke the deviants. But the agency has now opted to roll out the campaign next month.

The posters read, “Sexual harassment is a crime in the subway, too – a crowded train is no excuse for an improper touch. Don’t stand for it or feel ashamed, or be afraid to speak up. Report it to an MTA employee or police officer.”

The first 2,000 posters will be distributed throughout the system and should remain up for at least three months to “assess its impact,” said NYC Transit spokesman Paul Fleuranges.

The campaign was sparked by a report last year by Manhattan Borough President Scott Stringer that found 10 percent of women surveyed claimed to have been sexually abused and 63 percent reported having been sexually harassed.