The Beady Eye frontman's film company, 1 Productions, is developing the movie adaptation of Richard DiLello's 1973 book, The Longest Cocktail Party, and Gallagher is keen to cast the Dallas Buyers Club star, who ironically played John Lennon's killer Mark David Chapman in 2007 drama Chapter 27.
Gallagher is preparing to hold castings in Los Angeles in April (14), and Leto, as well as Before Midnight's Ethan Hawke, are on the shortlist to star in the movie, according to the U.K.'s The Sun newspaper.
An insider tells the publication, "He knows he's not going to manage to entice someone like Brad Pitt but he wants high-calibre people who are more on the indie scene of Hollywood. He thinks actors such as Jared and Ethan would be perfect."
The Longest Cocktail Party details DiLello's tenure at the Beatles' Apple company, and covers the band's peak years from 1968 to the split in 1970.