* Kenya accused of backing warlord in controlof Kismayu
* Kenya says al Shabaab will fill any political vacuum
By Drazen Jorgic
NAIROBI, Aug 6 (Reuters) - Kenya said on Tuesday it was ready to hand control of the strategic Somali port city of Kismayu to a recognised leader, but warned that a chaotic exit would embolden al Qaeda-linked insurgents in southern Somalia.
Kenyan troops, as part of an African Union peacekeeping force, routed al Shabaab rebels from Kismayu in September but fighting flared up and dozens of civilians died as rival warlords have battled in recent weeks for control of the lucrative trade flowing through the city's port.
Tensions have been simmering for months between Kenya and the central Somali government, which accuses Nairobi of backing Ahmed Madobe, a former warlord whose militia fought beside the Kenyans and who now controls Kismayu. Mogadishu opposes Madobe's leadership.
"The government of Kenya is ready to handover the two ports but it must hand over to someone and that someone must be a negotiated process," Kenya's Foreign Affairs Principal Secretary Karanja Kibicho told a news conference, referring to the city's airport and seaport.
"Otherwise if (Kenya) just left, we would be sliding back to where came from."
In a country where political support and access to resources is founded on clan loyalties, Somalia's central government has struggled to exert its influence over its many regions and agree on how to share power under a federal political system.
In a sign of how bitter the argument has become, the semi-autonomous Puntland region on Monday broke off all ties with Mogadishu. Analysts say the southern Jubaland region, which includes Kismayu, could follow if Mogadishu mishandles the situation.
A breaking-up of the state would risk a reversal of security gains against the rebels in a country long seen as a launch pad for militant Islam in the region and beyond.
The AU peacekeeping force, known as AMISOM, has forced al Shabaab to relinquish control of key urban bases but the militants still hold sway over large rural areas.
Neighbouring countries with forces inside Somalia are frustrated at Mogadishu's failure to establish regional or local administrations in areas won back from al Shabaab.
"The AMISOM troops are stuck. They cannot move forwards," said Zaddock Madiri Syong'oh, an adviser at Kenya's foreign affairs ministry. "If they move, al Shabaab comes immediately and takes over liberated areas."
Kenya sent troops into Somalia in part to create a buffer zone between al Shabaab and its porous border with the Horn of Africa country.
The Mogadishu government is in talks with Madobe, who Kenya denies backing, over who will administer Kismayu and how proceeds from the port and the city's airport be shared out.
Kibicho said the Kenyan government would have to be confident al Shabaab could not thrive in Jubaland, which abuts the border, before it hands over control. (Editing by Richard Lough and Sonya Hepinstall)