* Jonathan seen ahead in main polls
* Ruling party expected to lose some states
* Buhari seen as main rival, Ribadu remote third
LAGOS, March 22 (Reuters) - Nigerian President Goodluck Jonathan is on course to win April elections but the ruling People's Democratic Party (PDP) could lose control of several states, according to local opinion polls.
The surveys, published in Nigerian newspapers this week, vary widely in detail and scientific quality -- one claimed to have had 70 million SMS responses, roughly equivalent to every adult in the country -- but they broadly show a common trend.
A poll published by the This Day newspaper carried out with global research group Ipsos showed just over 60 percent of respondents would vote for Jonathan, with his nearest rival, former military ruler Muhammadu Buhari, on 22 percent.
But it said the picture was different at a regional level.
"A noticeable trend is the likelihood that the PDP may win the governorship in a state and lose the presidential in the same state, or vice versa," it said.
Nigeria holds presidential elections on April 9, with parliamentary elections a week earlier and governorship elections in the 36 states a week later. [ID:nLDE6AM2BY]
The PDP candidate has won every presidential race in Africa's most populous nation since the end of military rule 12 years ago and history is expected to repeat itself in April.
But to win in the first round, Jonathan needs to secure 25 percent of the vote in at least two thirds of the states, or else he will face a run-off with his nearest rival.
Buhari -- a disciplinarian who ruled between December 1983 and August 1985 and is best remembered for his "War Against Indiscipline", a campaign against corruption -- is expected to win strong support in parts of the north. [nLDE72F2I3]
The This Day/Ipsos poll -- carried out between Feb. 25-March 16 in all 36 states and the capital Abuja -- gave Buhari a clear lead in five northern states and a narrower lead in six others.
RIBADU SEEN DISTANT THIRD
Former anti-corruption chief Nuhu Ribadu is hoping to secure strong backing for his presidential bid in the southwest, the stronghold of his Action Congress of Nigeria (ACN) party, but the poll put him on just 4.7 percent of the overall vote.
It said 92 percent of respondents in Nigeria's most populous city of Lagos, in the southwest, would vote for sitting state governor Babatunde Fashola (ACN) in the governorship election, but 80 percent would vote Jonathan for the presidency.
Jonathan inherited power after the death of late northern President Umaru Yar'Adua last year and is seeking what would have been Yar'Adua's second term.
Buhari is hoping to capitalise on northern resentment at his candidacy but would need Ribadu to perform well in the southwest if he is to have a hope of forcing a run-off.
A second poll carried out by local firm NOI Polls, which has a partnership with Gallup, said 68 percent of Nigerians approved of Jonathan's performance so far as president.
The poll, commissioned by Nigerian civil society group the ANAP Foundation, said 53 percent of respondents expected Jonathan to win the April polls.
It said 73 percent of those questioned were aware that Buhari was running for president, while only 48 percent were aware that Ribadu was standing.
Jonathan has just completed a high-profile tour of the 36 states. Buhari's campaign is ongoing, while Ribadu's has been comparatively low key. (For full Reuters Africa coverage and to have your say on the top issues, visit: af.reuters.com/ ) (Writing by Nick Tattersall; Editing by Giles Elgood)