(Corrects date when Saleh stepped down in paragraph 5)
SANAA, Jan 3 (Reuters) - Yemen's ousted president will go abroad for medical treatment, an aide said on Thursday, and his opponents say his absence will improve the chances of success in reconciliation talks seen as crucial for stabilising the impoverished country.
The talks are expected to start in February.
Ali Abdullah Saleh, expected to be absent during the discussions, remains influential, and his continuing sway over Yemen is worrying Gulf neighbours and Western nations who fear the political transition could descend into chaos.
Restoring stability in Yemen has become a priority for the U.S. and its Gulf allies fearing that Islamist militants will further entrench themselves in a country neighbouring top oil exporter Saudi Arabia and lying on major world shipping lanes.
Yemen's Gulf neighbours, led by Saudi Arabia, sponsored a deal that saw Saleh quitting in February 2012 after a year of protests against his rule and allowed his deputy, Abd-Rabbu Mansour Hadi, to take office.
The power transfer deal mandates Hadi to oversee reforms during a two-year interim period to ensure a transition to democracy, including amending the constitution and restructuring the armed forces to break the Saleh's family's grip.
Yemeni sources said pressure has been mounting for Saleh to
leave Yemen to ease lingering political tensions, particularly after his announcement that he would head his party, the General People's Congress (GPC), in the national talks.
"Some political parties have told President Hadi that they will not take part in the national dialogue if Saleh did not leave Yemen," one government source told Reuters. Saleh was expected to travel to Saudi Arabia for treatment, he said.
A presidential palace source confirmed that Saleh was set to leave Yemen for treatment in Saudi Arabia before talks.
Saleh's press secretary said there were plans for him to travel to Saudi Arabia, the United States or Italy, for medical treatment and "not as part of a political deal". He said the date of his trip was yet to be finalised.
Last year, Saleh, 69, went to the United States for treatment of wounds inflicted in an assassination attempt in 2011.
For decades, the United States and Saudi Arabia saw Saleh as an ally who could contain Islamist militants operating in Yemen. His ruling party has half the seats in the transition cabinet and his opponents fear he could be a disruptive influence at the talks.
Last month, Hadi ordered a broad overhaul of the military, which is divided between Saleh's opponents and supporters. His decree abolished the elite Republican Guard, led by the former leader's son, Brigadier-General Ahmed Saleh. (Reporting by Mohammed Ghobari in Sanaa and Rania El Gamal in Dubai; Writing by William Maclean; Editing by Louise Ireland)