FACTBOX-Political risks to watch in Sudan and South Sudan

KHARTOUM/JUBA, Feb 20 (Reuters) - Sudan and South Sudan are deadlocked on a long list of disputes stemming from their split in 2011, blocking cross-border oil flows and undermining stability in both countries.

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

Following are some factors to watch:

TENSIONS ON THE BORDER

Khartoum and Juba 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 Neither side has withdrawn its army from the border, as agreed as a condition for oil flows.

What to watch:

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

- Resumption of cross-border flows. 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

The oil shutdown by South Sudan has worsened an economic crisis in Sudan where oil used to be the main source of revenue as well as foreign currency needed for imports.

Small protests have become more frequent as people fret about rising prices and corruption. Annual inflation hit 43 percent in January, up from 15 percent in June 2011, before South Sudan seceded.

President Omar Hassan al-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 larger groups?

SOUTH SUDAN'S 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 thanks to tax increases and reserves but experts estimate the central bank could run out of money.

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 Sonya Hepinstall)