REUTERS - Somalia's new prime minister appointed the leader of a major Islamist militia to the post of interior minister and made a key ally of the president the finance minister when he named his cabinet on Friday.
 

The country's new Islamist president, Sheikh Sharif Ahmed, and Prime Minister Omar Abdirashid Ali Sharmarke face the daunting task of bringing peace to the failed Horn of Africa state after 18 years of violence.
 

Key to their success will be persuading the many Islamist groups that fought Ethiopian troops to back the government, and isolating hardline al Shabaab fighters who have declared war on the new administration and are on Washington's list of terrorist groups.
 

According to a cabinet list from the prime minister's office, Sharmarke appointed Abdulkadir Ali Omar as interior minister and Sharif Hassan Sheikh Aden as deputy prime minister and finance minister.
 

Omar was deputy chairman of the Islamic Courts Union that ousted warlords from Mogadishu and ran the capital before it in turn was driven from power by invading Ethiopian troops in late 2006.
 

Omar is based in the capital and is the leader of one of the strongest moderate Islamist militias in the country.
 

He was against moves by the opposition Alliance for the Re-Liberation of Somalia to reconcile with the Western-backed interim government under a U.N.-hosted peace process in neighbouring Djibouti.
 

He changed his tune when Ahmed, who was chairman of the Islamic Courts and then an ARS leader, was elected president by parliament in January.
 

New finance minister, Hassan, was parliament speaker when Ethiopian troops intervened. He resigned and was a founder of the ARS. He was a key player in the peace process that saw the ARS join parliament and elect the president. The new foreign minister is Mohamed Abdullahi Omaar, the elder brother of award-winning journalist Rageh Omaar. The minister for internal security is Omar Hashi Aden, a former colonel and chairman of the joint security committee of the ARS.