ADDIS ABABA (Reuters) - Ethiopia, which has deployed hundreds of troops inside Somalia to rout Islamist insurgents, is set to withdraw from the war-ravaged country by the end of April with Djibouti, Uganda and Burundi poised to step in, the African Union said on Friday.
Ethiopian forces captured the rebel stronghold of Baidoa in southern Somalia last month having seized Baladwayne from the al Qaeda-allied al Shabaab group on New Year's Eve.
Troops from Ethiopia crossed the border in November to open up a third front against the militants, who are also fighting 9,000 Ugandan and Burundian troops under the African Union Mission in Somalia (AMISOM) and Kenyan forces to the south.
Keen to point out their incursion is not a repeat of their ill-fated 2006-2009 war in Somalia, Ethiopian officials have said troops would only be deployed for a brief period.
Earlier this month, the U.N. Security Council voted to expand AMISOM, which supports the shaky Western-backed government, to nearly 18,000 soldiers, and will include Kenyan troops who will "re-hat" to its blue berets.
Chiefs of staff from troop contributing countries met in Addis Ababa to iron out details of the expanding mission.
"It provides for Djiboutian forces to be deployed in Baladwayne by the end of April at the latest. Two thousand five hundred troops from Burundi and Uganda will also be deployed in Baidoa by the 30th of April at the latest," the AU's Ramtane Lamamra said of a deal signed by the officials.
"The decision up to now is that it is essentially Baladwayne and Baidoa (for Ethiopia) and they have to be handed over to AMISOM and then Ethiopia will withdraw its forces to its own national territory."
Lamamra, the bloc's commissioner for peace and security, also said a Djiboutian contingent would be deployed in Mogadishu.
Ethiopian soldiers previously went into Somalia in 2006, and left in early 2009 after pushing the Islamist Islamic Courts Union out of the capital Mogadishu.
At the time, most Somalis opposed the intervention and analysts said it may have encouraged people to join al Shabaab.
Lamamra, however, said there was a slim possibility the bloc could ask Addis Ababa to push further.
"Because Ethiopian troops are assisting ... without being re-hatted unlike Kenya - it means this effort is being done on national resources and national budget, I don't see how we can ask them to go further, to do more if there is no accompanying support package," he said.
"If we succeed to work out some support package for Ethiopia, we may be in a position to request the government to consider the possibility to help us elsewhere."
Lamamra also said Sierra Leone was expected to deploy a battalion of 850 troops in southern Somalia by the end of June.
Somalia has been in turmoil since warlords toppled dictator Mohamed Siad Barre in 1991. Fighting has killed more than 21,000 people since al Shabaab launched its insurgency in 2007.
Al Shabaab rebels, who want to impose a harsh interpretation of sharia law on the Horn of Africa nation, have waged a five-year campaign to drive Somalia's weak government from power.