After adopting second son Pax Thien from South Asia - the same region of the world as elder son Maddox, Jolie is said to be keen to add another child from daughter Zahara's continent Africa.
And, reports state that the new addition to the Jolie-Pitt family will come from Zahara's nation Ethiopia.
"Brad and Angie have made no secret of the fact that they are keen to extend their rainbow family," the Daily Mail quoted a source, as saying.
"But they've always been very careful to ensure that they leave enough time between kids so that that each child fully integrates into the family and feels truly settled.
"Angie in particular feels very strongly that while Shiloh will grow up seeing the family resemblance between herself and her natural parents, and Maddox and Pax will feel a connection through their birthplaces, Zahara has no such close-knit bond.
"They hope that by finding an Ethiopian brother or sister - preferably sister - for her, it will help Zahara feel more comfortable and happy in her own skin.
"Both Brad and Angelina are incredibly excited about the latest addition to the Jolie-Pitts and if anything will bring them closer together, then this is it," the source added.
The couple are said to have planned a visit to Ethiopia's Wide Horizons agency in November, the same adoption agency that helped them get Zahara.