Brad Pitt is asking a judge to grant him joint custody of his six children in his split from Angelina Jolie Pitt, according to a divorce filing.

The actor's request was included in his response to Jolie Pitt's September 20 petition to end their two-year marriage. The actress sought sole physical custody of their six children, aged from eight to 15.

Custody has been the major issue in the break-up so far, with authorities investigating Pitt over what happened during a dispute on a private flight with his family in mid-September.

The couple reached a temporary custody agreement that allowed the actor to visit his children while the investigation by a child welfare agency in Los Angeles continues.

The outcome of the investigation could impact how a judge determines custody arrangements, although courts in California generally favour awarding joint custody. The actors could also reach a private agreement that would not involve a public custody fight in court.

The couple got separated last September.

Pitt's filing does not include any new details about the couple's break-up. Pitt cited irreconcilable differences and makes no mention of a pre-nuptial agreement that will govern how the pair divides their assets.

He also cites September 15 as the day of their separation, one day after the alleged plane altercation between him and his 15-year-old son Maddox.

Pitt was accused of being abusive toward the teenager, sources said, but authorities were not notified when the plane landed in Minnesota.

Several sources said the incident was being investigated by the Los Angeles County Department of Children and Family Services, but the agency said it could not confirm whether it was involved.

The actors were together for 12 years after becoming close while filming Mr & Mrs Smith in 2005.

As one of Hollywood's elite power couples, the actors transformed the flurry of headlines into a force for good.

They adopted children from Cambodia, Vietnam and Ethiopia. In 2006, they formed the Jolie-Pitt Foundation, to which they funnelled many of the millions they made selling personal pictures to celebrity magazines.

Jolie Pitt, who became special envoy for the United Nations in 2012, became an outspoken voice for refugees, as well as for breast cancer treatment after undergoing a double mastectomy herself. Pitt built homes in New Orleans for victims of Hurricane Katrina.

The pair recently sold a home they purchased in New Orleans' French Quarter for 4.9 million dollars (£4m).

Their only other on-screen role together is in 2015's By The Sea, about a troubled American couple on holiday in France.

Pitt skipped the September 28 premiere of the Terrence Malick's new documentary Voyage Of Time: The IMAX Experience, which he narrated. In a statement he said he was "currently focused on my family situation and don't want to distract attention away from this extraordinary film".

Pitt stars with Marion Cotillard in Robert Zemeckis' upcoming spy thriller Allied.

Earlier this year Jolie Pitt finished shooting First They Killed My Father, her fourth feature as director. The film, about the 1970s Khmer Rouge regime, was shot in Cambodia.