"I am delighted that Angelina Jolie will be playing my role in the adaptation of my book," Daily Variety quoted Pearl as saying. "I deeply admire her work and what she is committed to."

English filmmaker Michael Winterbottom, famed for such war-based films as "Welcome to Sarajevo" and "The Road to Guantanamo," will direct reports People Magazine .

"A Mighty Heart" will be co-produced by Plan B, the production company Pitt and his wife, Jennifer Aniston, founded. Pitt and Aniston, who were divorced last year, remain co-owners of the company.

"The film will focus on the deep collaboration between people around the world in search of Daniel in 2002," Pitt tells PEOPLE. "We hope the film can increase understanding between people of all faiths and portray the story and the people involved as honestly as possible without anger or judgment."

Contrary to reports claiming that Pitt's ex, Jennifer Aniston, was earlier cast as Mariane Pearl, a rep for Pitt and Jolie tells PEOPLE, "Jennifer was never attached to that role. When the project was first brought to Plan B, Jen was a partner in the company at the time."

It is the first announced on-screen role for Jolie, 31, since the birth of daughter Shiloh Nouvel, born in Namibia in May. The couple have two older children, 18-month-old Zahara, adopted from Ethiopia, and 4-year-old Maddox, adopted from Cambodia.

Pitt, 42, and Jolie first collaborated as co-stars in last year's "Mr. & Mrs. Smith."