Robert Offer said in a statement that Jolie’s decision had been made “for the health of the family.”
He added: “She will not be commenting and asks that the family be given privacy at this time.”
Jolie, 41, cited irreconcilable differences with Pitt, listing their date of separation as 15 September.
The nature of the differences has not been revealed but TMZ reports there was conflict over Pitt’s parenting, with a source saying Jolie was “extremely upset with his methods.”
Reacting to Jolie’s decision to end their marriage, Pitt said: “I am very saddened by this but what matters most now is the well-being of our kids.
“I kindly ask the press to give them the space they deserve during this challenging time.”
The couple have six children – Maddox, 15, Pax, 12, Zahara, 11, Shiloh, 10, and eight-year-old twins Knox and Vivienne.
Jolie is seeking custody of all of them with visitation rights for Pitt and she does not want spousal support.
The pair, known as Brangelina, married in a private ceremony in France in 2014 but they had been together since 2004.
They had first met on the set of the film Mr And Mrs Smith, while Pitt was still married to Friends star Jennifer Aniston.
Jolie had been married twice before - to actors Jonny Lee Miller and Billy Bob Thornton.
She is being represented in these proceedings by divorce lawyer Laura Wasser, who helped her divorce Thornton and is also representing Johnny Depp in his divorce from Amber Heard.
Sky News Entertainment Correspondent Lucy Cotter said: “Since they met on the set of Mr and Mrs Smith in 2004 there’s been intense interest and speculation about Hollywood’s ultimate power couple.
“Brad Pitt’s divorce from the ‘girl next door’ Jennifer Aniston shortly afterwards did nothing to diminish the fascination in Brangelina.
“Since then the global media has scrutinised their every move and followed their growing brood around the world, despite the couple guarding their privacy fiercely.
“The news that they are divorcing will do nothing to stop global interest in the couple with rumours about the real reasons surrounding the split already dominating social media.”
As well as their film careers, Pitt and Jolie are both known for charitable work: they set up the Maddox Jolie-Pitt Foundation 10 years ago to assist in humanitarian crises around the world, launching it with a $1m donation to Medicins Sans Frontiers.
Jolie represented the UN High Commission for Refugees as a goodwill ambassador between 2001 and 2012, becoming a special envoy in April 2012.
She has also been a well-known symbol in the battle against cancer, having undergone a double mastectomy and removal of her ovaries and fallopian tubes to prevent an aggressive form of the disease that killed her mother, aunt and grandmother.
Pitt started the Make It Right Foundation after Hurricane Katrina in 2005, donating $5m (£3.8m) to help rebuild New Orleans after the disaster.
The 52-year-old is currently focusing on opening a luxury resort in Croatia. (Sky News)
•Photo shows Angelina Jolie and Brad Pitt in happier times.
