Publisher Vanessa Springora ignited a huge scandal in France earlier this year with her memoir “Consent”, in which she described how she was groomed by Matzneff when she was 14.
Two other women have since come forward to say they too were abused by him as teenagers.
Matzneff, who never made a secret of his preference for sex with adolescent girls and boys, is to stand trial in September on a charge of promoting paedophilia.
Prosecutors have also launched a rape investigation into the diarist, long notorious for his 1974 defence of paedophilia, “Les Moins de Seize Ans” (“The Under 16s”).
Matzneff, now 83, told French television in January that he regretted past trips to Asia to have sex with minors, claiming that at the time “no one ever said it was a crime”.
The scandal has shaken the French literary establishment, in which for years Matzneff occupied a privileged niche, winning the prestigious Renaudot prize in 2013.
Last week a deputy mayor of Paris was forced to resign because of his links to the writer.
The producers of the film said it would be directed by the rising French star, Vanessa Filho, whose debut film “Angel Face” premiered at the Cannes film festival in 2018.
She is also writing the script.
The Matzneff scandal was one of the turning points in the #MeToo movement in France, after decades of people turning a blind eye to the diarist’s behaviour despite his frankness about his private life.
Within months of the latest instalment of his “intimate journals” hitting the shelves, French publishers began pulling his books from shops as Springora’s book began making headlines in January.
Matzneff denounced the “unjust and excessive attacks” on him, claiming that his relationship with Springora had been one of “beauty”.
But in her book, which quickly became a bestseller, she wrote: “Aged 14, you are not supposed to have a 50-year-old man waiting for you when you leave school.
“You are not supposed to live in a hotel with him, or find yourself in his bed with his penis in your mouth when you should be having your mid-afternoon snack.”
Springora said Sunday that her book had helped her “be honest with myself and take back my own story.
“‘Consent’ helped me reinvent myself,” she told the JDD newspaper.
“Today I feel that I have closed a chapter [of my life] and I can move on. But it will always be [a part of] me,” she added.