By Nick Tattersall

LAGOS, Sept 9 (Reuters) - Momentum appears to be buildingtowards an election bid by Nigerian President Goodluck Jonathan,but the real political horsetrading has yet to begin if he is tocarry the whole country with him.

Jonathan, in his trademark fedora and traditionalcaftan-like attire, has kept Africa's most populous nation ontenterhooks for months, declining to say whether or not he plansto seek re-election in the polls due in January.

The stakes are high either way in a country that has seenrepeated outbreaks of religious and communal violence, and hisreticence is born of well-grounded caution, observers say.

Parts of the Muslim north will feel aggrieved if heannounces a bid because, as a Christian southerner, they say hewould be breaking an unwritten pact that power rotates betweennorth and south every two terms.

But he is the first Nigerian leader from the Ijaw ethnicgroup in the restive Niger Delta, and a failure to stand wouldprovoke protest in his home region, the heartland of thecountry's mainstay oil and gas industry.

"Jonathan has continued to tread very carefully as far asmaking public his plans for the future, as he knows there willbe tremendous blowback from his political opponents if and whenhe announces he will run," intelligence firm Stratfor said.

"It is no secret that Nigeria's northern elites oppose whatthey see as a southerner trying to usurp their rightful place inpower. The level of protest that leading northerners havesustained so far is nothing in comparison to what it will be ifand when Jonathan actually declares his candidacy."

At a late-night meeting in the presidential villa onTuesday, Jonathan told powerful state governors in the rulingPeople's Democratic Party (PDP) that he intends to stand, one ofthe governors who attended the meeting said.

Imo State Governor Ikedi Okahim made the remarks in front oftelevision cameras, and his comments were quickly broadcast onboth state-run and private stations, leading many analysts toconclude it was a deliberate move to test the waters.

"(Okahim) was most likely preparing the ground for apossible formal declaration next week by the president ... togauge initial reaction," said Kayode Akindele, a Lagos-baseddirector at financial consultancy Greengate Strategic Partners.

"The president will only declare if he is confident ofwinning the primaries ... There is a feeling of renewed swaggerin the recent steps of the president and his close circle butreal horsetrading of the PDP primaries commences next week."

ACTIONS NOT WORDS

Jonathan kept his cards close to his chest in a message toMuslims on Thursday to mark the end of the fasting month ofRamadan, reaffirming his commitment to ensure free and fairelections and pledging to push ahead with reforms.

"With your continued support and goodwill, we shall, in thecoming months carry forward our plans to further stabilize allsectors of our economy, improve national infrastructure andpower supply," he said.

His recent actions have been more telling than his words.

Jonathan replaced the heads of the armed forces, police andstate security service on Wednesday, a day after the electoralcommission announced the timetable for polls.

He named Major General O.A. Ihejirika as his new chief ofarmy staff, the first time since Nigeria's 1967-70 civil warthat anyone from the southeastern Igbo ethnic group has held thetop post in the most powerful branch of the armed forces.

Should the rotation agreement be upheld and the nextpresidential term goes to the north, the Igbo would feel theirturn had come in 2015 when it rotates back to the south. AJonathan win in 2011 would scupper that hope, and Ihejirika'snomination is seen by some as a way of ensuring loyalty.

The election timetable announced this week says partyprimaries begin on Saturday and run to the end of October.

Jonathan has already been meeting former heads of state andother political heavyweights including his rivals in recentweeks, such as ex-military leader Ibrahim Babangida and formervice president Atiku Abubakar, both of whom have said they willrun against him to seek the PDP nomination.

The state governors form a powerful caucus in the PDP andwinning their support will be key to Jonathan's chances ofsuccess. Those from his home region have already vowed to backhim, but those from the north have stopped short of doing so,saying simply they recognise his right to contest.

Several northern governors were absent at Tuesday's meetingwith Jonathan, having travelled to Saudi Arabia to mark the endof Ramadan, This Day newspaper said, without naming its sources.

The newspaper said none of those present raised objectionsto Jonathan's plans to run, but that they said another meetingshould be held next week with all governors attending.

"Caution is an instinct that has served Jonathan well in aremarkable political career," said Antony Goldman, London-basedhead of PM Consulting and a Nigeria expert.

"If he declares publicly, it will be because he is confidentof winning and of holding the PDP together. His declaration isalready so widely anticipated that any early leak, accidental ordeliberate, is unlikely to have a significant impact." (For more Reuters Africa coverage and to have your say on thetop issues, visit: http://af.reuters.com/ ) (Writing by Nick Tattersall; editing by Ralph Boulton)