KHARTOUM/JUBA, Jan 15 (Reuters) - Sudan and South Sudan are locked in a long list of disputes stemming from their split in 2011, blocking cross-border oil flows and undermining stability in both African countries.

South Sudan seceded in July 2011 under a peace agreement that ended decades of civil war but both countries have been unable to secure their border, agree on ownership of disputed territories and resume oil exports.

Following are some factors to watch:

KHARTOUM-JUBA DISPUTES

The neighbours agreed in September to restart oil exports from the landlocked South through the north after coming close to war in April. Neither side has withdrawn their army yet from the border, as agreed as condition for oil flows.

What to watch:

- More negotiations. The worst situations in the past few years came about whenever they stopped talking.

- Will cross-border flows resume? This would give both economies a boost and an incentive to keep talking.

- Insurgents have taken up arms in Sudan's Blue Nile and South Kordofan border states. Will Sudan agree to political talks as demanded by the African Union? Continued fighting would undermine border security as the rebels control part of the border to South Sudan.

SUDAN'S ECONOMIC CRISIS

South Sudan's oil shutdown has worsened an economic crisis in Sudan where oil used to be the main source for the budget and foreign currency needed for imports.

Khartoum has avoided an "Arab Spring" but small protests have become more frequent as many Sudanese fret about prices. Annual inflation hit 44 percent in December, up from 15 percent in June 2011, the last date before southern secession.

Bashir also faces dissent from his ruling circles.

What to watch:

- Will the Sudanese pound fall further, hitting Sudan's ability to import? Will food inflation rise further?

- Any signs of bigger protests? Will the weak opposition be able to unite and mobilise bigger protests?

SOUTH SUDAN STABILITY

South Sudan's economy is showing signs of strain due to the loss of oil revenues which made up 98 percent of state income until the shutdown. Juba says the situation is under control but experts estimate the central bank could run out of reserves.

What to watch:

- How long can the South survive without oil? Will essential food items and fuel get scarce? Will the South Sudanese pound lose further ground on the black market?

(Reporting by Ulf Laessing and Hereward Holland; Editing by Angus MacSwan)

((ulf.laessing@thomsonreuters.com)(Khartoum newsroom)(+249 927 000 086)(Reuters Messaging: ulf.laessing.reuters.com@reuters.net))

Keywords: SUDAN SOUTH/RISK