The female portion of the cast of Aaron Sorkin’s HBO pilot is taking shape. Olivia Munn and Alison Pill are in negotiations for supporting roles in the project, while I hear Marisa Tomei is inching closer to committing to play the female lead. Tentatively titled More As This Story Develops, the project centers on cable news anchor Will McCallister (Jeff Daniels), who has his own show, as well as the show’s female executive producer and staff. Tomei, repped by CAA and Untitled, is poised to play the executive producer, MacKenzie, for whom producing the news is what she does best and everything else is tied for last place. Pill will play Maggie, an associate producer on the assignment desk. Munn, repped by CAA and Mosaic, will play a sexy financial analyst on the same cable network as McCallister.

Oscar winner Tomei has been one of several actresses considered for MacKenzie and the most heavily pursued by the producers. Said to be a big fan of Sorkin’s, she met with him earlier last week and again on Saturday when he attended her off-Broadway play Marie and Bruce. (Among the other contenders for the role, Emily Mortimer had emerged as a frontrunner.) Munn, who stars on NBC’s midseason comedy Perfect Couples, was courted for several broadcast pilots this pilot season but opted not do any. She continues to be a correspondent on Comedy Central’s The Daily Showand co-stars in the upcoming Miramax movie I Don’t Know How She Does It. Tony nominee Pill, repped by WME and Joannie Burstein, already has experience as a regular on an HBO series — she co-starred on the second season of In Treatment. She recently co-starred in Scott Pilgrim vs. the World.