Judi Dench, Martin Clunes, Michael Sheen, Samantha Bond, Miriam Margolyes, Michael Hordern, Amanda Root, John Moffat and Terence Alexander. It was excellent.
L.A. Theatreworks also has a dramatization available on Audible -- but the cast isn't half as famous as Judi Dench et al. I would love to get my hands on that performance but Audible does not make it easy to find out who the cast actually is. Hol, who is the publisher of the edition you listened to?
https://www.imdb.com/title/tt0044744/?ref_=nv_sr_5?ref_=nv_sr_5