According to reports Charlize Theron and Sean Penn are planning to adopt

Los Angeles - Charlize Theron and Sean Penn are reportedly planning to adopt.

The Hollywood couple are said to be moving in together and the South African actress is eager for her son Jackson, two - who is also adopted - to have a brother or sister.

A source said: "Charlize was an only child and always wished for a brother or sister. It's important to her that Jackson have a brother or sister."

Sean - who has grown up daughter Dylan, 23, and son Hopper, 20, with his ex-wife Robin Wright - is said to be particularly keen to adopt from Haiti, the island where he has done much charity work since it was hit by an earthquake in 2010.

The source added to America's OK! magazine: "Sean is passionate about Haiti. He's done a lot of work there and thinks adopting form Haiti makes sense. They hope to adopt by the end of the year."

It was recently reported that Sean has 'baby-proofed' his Malibu home ready for Charlize and Jackson to move in, by erecting a new fence around the swimming pool in the back garden, and bringing in a trampoline.