Cumberbatch would join Emma Stone and Charlie Hunnam.
Plot details are unknown as del Toro and Lucinda Coxon work through a rewrite on a script del Toro and Matthew Robins originally penned.
Legendary will produce and be a participating financing partner on the movie, with Universal Pictures retaining an option to finance at a later date. The film is set to begin shooting in February.
It’s another major part for Cumberbatch, whose schedule has been packed of late.
Among his roles this year: “Star Trek Into Darkness,” “12 Years a Slave,” “August: Osage County” and “The Hobbit: The Desolation of Smaug.” He is currently filming “The Fifth Estate” where he will play WikiLeaks founder Julian Assange. He’s also busy with TV work with the third season of the BBC’s “Sherlock” about to go into production and HBO’s “Parade’s End,” which bowed in February.
Cumberbatch is repped by UTA and Conway van Gelder Grant.