* Intense lobbying expected ahead of primaries

(Adds quotes from president)

By Felix Onuah and Camillus Eboh

ABUJA, Sept 18 (Reuters) - Nigerian President Goodluck
Jonathan showed the power of incumbency on Saturday, mustering
the support of more than two thirds of powerful state governors
for the launch of his re-election campaign.

Thousands of cheering supporters gathered in Abuja's central
Eagle Square to hear Jonathan proclaim his candidacy for the
January election, shaping up to be the most fiercely contested
since the end of military rule.

"Our country is at the threshold of a new era, an era that
beckons for a new kind of leadership, a leadership that is
uncontaminated by the prejudices of the past," said Jonathan, in
his trademark fedora and traditional kaftan-like attire.

He listed ending power shortages, improving health and
education and ensuring food self-sufficiency among his
priorities. He also pledged to better manage oil revenues with a
planned sovereign wealth fund and told kidnappers and criminals
"that give us a bad name" to be ready for battle.

The election bid by Jonathan, from the oil-producing Niger
Delta in the south, faces resistance from some parts of the
north as it breaks an unwritten agreement that power should
rotate between the country's main regions every two terms.

But analysts predicted Jonathan would only announce his
candidacy if he was sure of winning enough support from within
the ruling party. Saturday's rally seemed to demonstrate he had
built up that confidence over recent weeks.

"The northeast zone will rally round you and we assure you
that we will deliver you the highest number of votes come 2011,"
Isa Yuguda, governor of northeastern Bauchi state and once seen
as a potential presidential contender, told the rally.

Jonathan inherited the presidency when president Umaru
Yar'Adua, a northerner, died this year during his first term,
and some powerbrokers in the ruling People's Democratic Party
(PDP) have said the next leader must be a northerner.

Key to Jonathan's fortunes at the mid-October primaries will
be the state governors, who form a powerful caucus within the
PDP. Twenty-six of the country's 36 governors, including several
northerners, spoke at Jonathan's rally in support of his bid.

But three of them were also at the Eagle Square parade
ground on Wednesday when former military ruler Ibrahim Babangida
launched his rival campaign, and it would have been political
suicide for the governors not to attend Saturday's rally.

"Nigerian politics has a Byzantine quality that makes it
hard entirely to be sure it's over until it's over," said Antony
Goldman, Nigeria expert and head of London-based PM Consulting.

"Jonathan is the front-runner. Northern rivals might hope to
deny him more than 50 percent of delegates and take the primary
to a run-off, but as things stand that would be quite an
achievement," he said.

LOBBYING AHEAD

The PDP nominee has won all three presidential races since
the end of military rule in 1999, making the outcome of past
elections a foregone conclusion and bringing Africa's most
populous nation close to being a one-party state.

But the presidential race this time is more contentious,
with no consensus PDP candidate and no obvious "godfather" --
the powerful background figures who have in the past hand-picked
the nominee -- holding sway over the party.

"In the next month the lobbying by all sides of hesitating
governors and others of influence is likely to be intense," PM
Consulting's Goldman said.

Babangida, a northerner who seized power in the OPEC member
in August 1985 and ruled for nearly eight years, also wants the
PDP ticket and is hoping northerners opposed to Jonathan will
rally behind him. He has vowed he would serve only one term.

But Babangida too is a divisive figure. He was forced from
power after cancelling an election that was generally regarded
as fair, and this colours his political reputation.

He faces other northern challengers within the PDP including
former vice president Atiku Abubakar, who switched to the ruling
party after running unsuccessfully for president as the
opposition Action Congress candidate in the last vote in 2007.

Kwara state governor Bukola Saraki and national security
adviser Aliyu Gusau could also win northern backing if they
decide to seek the PDP nomination, analysts say.

The threat to Jonathan from the northern factions depends on
their ability to unite behind a single candidate. Should
Babangida, Abubakar, Saraki and Gusau all push their campaigns
to the finish line, they may fail to do so.
(Writing by Nick Tattersall; editing by Janet Lawrence)