* Two strong northern candidates put pressure on Jonathan
* Babangida and Abubakar could split northern vote
* Jonathan yet to declare whether he will run
By Nick Tattersall and Felix Onuah
LAGOS/ABUJA, Aug 16 (Reuters) - Nigerian President Goodluck Jonathan's chances of winning vital support from the Muslim north for a 2011 election bid have suffered a setback after two rival northern candidates declared they would run against him.
Former military leader Ibrahim Babangida, known by his initials IBB, on Monday announced he would seek the ruling People's Democratic Party (PDP) nomination, a quarter century after first coming to power in a bloodless coup. [ID:nLDE67F0UA]
Former vice president Atiku Abubakar, who ran unsuccessfully for president as the opposition Action Congress candidate in the last polls in 2007, also declared he would seek the ruling party ticket on Sunday. [ID:nLDE67E0CK]
Both men are from Nigeria's Muslim north, meaning they are in a stronger position than Jonathan, a Christian from the southern Niger Delta, to win support from PDP traditionalists who believe that a "zoning agreement" must be upheld.
The unwritten pact says power should rotate between north and south every two terms to avoid political resentment in either of the country's two main regions. Under the deal, a northerner should run next year to complete what would have been the second term of late northern President Umaru Yar'Adua.
"There's a dominant view that it's the turn of the north, that the north has to serve out eight years. That's what turned Atiku to the PDP and what's making IBB come out," said Abubakar Momoh, politics professor at Lagos State University.
"Pitted against each other, they are going to split the northern vote ... but that does not mean Jonathan will have an easy sail. There are more northern candidates that will declare," he told Reuters.
Jonathan has not yet said whether he intends to stand in the polls. Sources close to him say he is concerned about the implications of ending zoning and about his own credibility as a candidate in elections he has pledged to make free and fair.
Analysts say he would only want to stand if he were guaranteed the polls would hand him a clear mandate to govern.
But his administration's recent policy announcements, from pledges to end chronic power shortages to major road-building projects, suggest he has ambitions to remain in office.
"Everybody knows that groups and interests are campaigning for him, and they are well-funded ... All of his key supporters are out there lobbying extensively for him," Momoh said, adding his failure to declare impinged on his credibility.
"Nobody is deceived," he said.
The PDP has officially hedged its bets, saying it recognises Jonathan's right to stand but also saying it wants to uphold the principle of zoning and that other candidates are welcome to present themselves at the primaries, expected next month.
That sets the stage for a fierce battle.
"There is still ambiguity (over zoning)," Babangida said in his declaration speech, a copy of which was read to Reuters by his spokesman on Monday.
"The most important thing is that they accept that all of us including Jonathan have the right to contest and I will exercise my franchise," he said.
In his declaration, Abubakar laid out five key priorities: creating jobs, improving power supply and infrastructure, fighting corruption and boosting security, education and health, and development in the restive Niger Delta oil region.
Both Abubakar and Babangida may find support from powerful northern state governors in the PDP, but they could struggle to win wider party backing. Abubakar was out of the PDP for three years, while Babangida commands only a minority following.
Even before Babangida declared, a website was set up for his campaign (www.voteibb.org) urging followers to donate, providing links to his Facebook and Twitter accounts, and allowing Blackberry users to scan a barcode for mobile updates.
On the website, Babangida pledges that he would not seek a second term if successful in 2011 and that he would work to ensure his successor was a southerner, in line with zoning.
A small minority of Nigeria's 140 million people have easy access to the Internet, but if Facebook popularity is anything to go by, Babangida will need to mount a strong campaign.
Just 136 people "like" his page, set up a week ago, compared to 162,915 fans on Jonathan's page, launched in late June. (For more Reuters Africa coverage and to have your say on the top issues, visit: af.reuters.com/ ) (Writing by Nick Tattersall; editing by Andrew Roche)