- AU says consensus solution is critical
* Madagascar risks plunging deeper into crisis
* Opposition boycotts election workshop
By Richard Lough
ANTANANARIVO, Jan 6 (Reuters) - International efforts to resolve a year-long political crisis in Madagascar must be redoubled to stop the Indian Ocean island from sliding deeper into turmoil, the African Union (AU) said on Wednesday.
Speaking at the opening of an international contact group meeting in Ethiopia, AU Commission Chairman Jean Ping called for the resumption of talks between Madagascar's feuding politicians over the formation of a power-sharing administration.
The AU's insistence on a consensus solution places it at odds with Madagascar's leader, Andry Rajoelina, who has repeatedly urged foreign mediators in recent weeks to stop meddling in the country's affairs.
"They (earlier power-sharing deals) are the fruits of consensus and are the only political and judicial basis from which to break the deadlock and end this crisis," Ping told the meeting in the Ethiopian capital Addis Ababa.
Rajoelina, 35, tore up a series of internationally-brokered agreements shortly before Christmas and appointed a senior military officer as prime minister to govern the country, which is increasingly eyed by outsiders for its oil and minerals.
Opposition leaders boycotted a two-day national workshop on Wednesday on preparations for parliamentary elections slated by Rajoelina for March 20 -- just over a year after he spearheaded the overthrow of former President Marc Ravalomanana.
The workshop "has no basis and is unilaterally organised, which breaks with the (power-sharing) deals signed previously in Maputo and Addis Ababa," Emmanuel Rakotovahiny, who had been named one of two co-presidents under the accords, told Reuters.
Ping did not mention the legislative poll in his speech.
Analysts are divided on how much leverage regional blocs including the AU, which suspended Madagascar after Rajoelina's power-grab, and foreign donors have in persuading Africa's youngest incumbent to return to talks.
France-based analyst Lydie Boka said donors still wielded carrots in the form of suspended aid worth hundreds of millions of dollars. "No private sector flows can compensate aid, even in the medium run," Boka told Reuters by email.
But others say Rajoelina might consider he has more to gain by breaking away from negotiations and hoping to obtain a semblance of legitimacy through the ballot box. (Additional reporting by Alain Iloniaina; Editing by Daniel Wallis and Elizabeth Fullerton)