The 'Snow White And The Huntsman' actress has filed papers at the Los Angeles County Superior Court, asking for spousal support and joint custody of their children Sykla, seven, and Tennyson, five.
Rupert has filed his response to the petition in which he also asks for joint custody and he has requested that he and Liberty split the court costs between them.
Liberty and Rupert's marriage has been under strain ever since his fling with 'Twilight Saga' actress Kristen Stewart was exposed last year.
Although Liberty initially kicked the director out of their home after his infidelity was revealed, they began couples therapy in an attempt to save their marriage.
A source said at the time: "It was Rupert's suggestion that he go to therapy with Liberty. He will do anything to save his marriage because he loves his wife and knows he screwed up.
"They have been married since 2003, and have two children together, they have a life together. Rupert is willing to do absolutely anything and everything he can to save his marriage, he knows this is the worst mistake of his life, and he cannot believe he was so stupid.
"The thought of losing his wife and children, who he loves more than anything in the world, is killing him."
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A 6ft shark from the Great White family has washed up on a Kerry beach. The female porbeagle shark was discovered by local photographer Bernard Fitzgerald at the weekend as he was walking on the Aughacasla beach in Castlegregory.
Astronaut Chris Hadfield's ability to make his adventures in space accessible to a wider audience has been credited by a minister for a large increase in the number of Leaving Certificate students choosing physics and other science subjects.
Construction work has started on a giant food village, complete with its own market garden, mini dairy and micro-brewery, for what organisers predict will be the country's largest outdoor food festival.
USA: A rampaging, 22lb Oregon house cat with a "history of violence" attacked a baby and trapped a family and their dog in a bedroom at their Portland home before being captured by police, authorities said.
Former Irish Nationwide chairman Michael Walsh wrote to the late minister for finance, Brian Lenihan, warning him against bank mergers as the financial crisis escalated, according to a letter obtained under the Freedom of Information Act.
One of the most senior doctors in the Department of Health, Colette Bonner, has responded to assertions from the wind lobby that her review on the health effects of turbines was "extremely limited and incomplete".