Sean Penn reportedly wants to rekindle his relationship with Charlize Theron.

The 55-year-old actor is reportedly ''still heartbroken'' following his split from the 40-year-old actress, but she refuses to return his calls.

A source said: ''Sean's friends urged him to call her. He's called her a few times.''

The former couple, who were rumoured to have gotten engaged in Paris last November, ended their romance in June after 18 months together, but the 'Milk' star can't stop thinking about the South African-born beauty.

The insider told InTouch Weekly magazine: ''He usually gets over romances quickly, but the more time that passed, the more he thought about Charlize. His ego is taking a big hit.''

While Sean is struggling to move on, the Oscar winner, 40, who has five-year-old son Jackson, adopted another baby, a girl named August, in July.

The actress is also currently working on new animation 'Kubo and the Two Strings' with Rooney Mara and Matthew Mcconaughey, having recently completed a string of films including 'The Last Face' and 'The Huntsman'.