Deadline understands that The Social Network and Moneyball producer won a bidding war for the rights to the Lesley Manville-fronted series ahead of a number of studios and rival producers.
Mum follows Cathy (Manville), a mother who is about to clock 60 and who deals with life’s crossroads in the wake of her husband’s death and turns a new leaf. She’s also surrounded by a zany family who she contends with.
The series, which airs on BritBox in the U.S., also stars Peter Mullan, Sam Swainsbury and Lisa McGrillis. A critical hit in the UK, with a number of BAFTA wins and nominations, the series launched on BBC Two in 2016 and its third season aired earlier this year.
Letts, who is also an actor and has appeared in Homeland and Divorce, is behind The Woman In The Window, his first screenplay not to be adapted from his own work, which is set to be released in 2020.
Rudin will exec produce alongside Big Talk boss Kenton Allen and original creator and writer Stefan Golaszewski.
Big Talk, which is backed by ITV, is currently working on an immigration comedy, Detained, with Will Arnett’s Electric Avenue for Sky, and recently optioned the Amaka crime novels from Nigerian author Leye Adenle.
Big Talk and Scott Rudin are represented by WME, Letts is repped by Abrams Artists Agency.