* Pope making first Africa voyage
* Will seek peace, support an end to corruption
* Pope says condoms will not stop spread of AIDS
YAOUNDE, March 17 (Reuters) - Pope Benedict embarked on his first trip to Africa as pontiff on Tuesday, seeking support for the continent during the world economic crisis and hoping to encourage peace and help tackle corruption.
The Pope starts his two-nation tour in Cameroon, where workers whitewashed walls, and rubble-strewn pavements cleared of street hawkers were swept in last-minute preparations on Tuesday.
Although the numbers of practising Catholics are dwindling in the developed world, Africa, where some progress has been made towards democratisation but conflicts and crises still simmer, is seen as vital to the future of a growing Church.
But the Vatican's controversial policy on condoms continues to be tested on a continent where AIDS has killed more than 25 million people since the 1980s.
While medical workers advocate the use of condoms to help prevent the spread of AIDS, the Church insists on fidelity within heterosexual marriage, chastity and abstinence.
"The problem cannot be overcome by distributing condoms. It only increases the problem," the pontiff told reporters on board the plane headed for Africa.
While in Cameroon, he will visit charities, meet Muslim leaders and attend a gathering of bishops trying to chart the Church's role in bettering Africans' lives. Later in the week, he will move on to Angola.
A billboard in central Yaounde showed a photo of the Pope and President Paul Biya, with the words "A perfect communion".
But many in the capital are sceptical, not least after the authorities destroyed market stalls last week in a bid to clean up the city ahead of the Pope's arrival.
"I am glad that he is coming but he should be here for religion and not other things," said 29 year-old Calvine Noumbisi, who squatted on the side of the road, selling rosaries, prayer books and incense rocks for a nearby church.
"If he prays, blesses the country and tells the politicians to confess, it will help us," she added.
Although Cameroon and Angola are both resource-rich nations, where oil has flowed for many years and millions of dollars worth of minerals have been dug from the ground, most of their inhabitants continue to live in grinding poverty.
This, many hope, will force the pope into also calling for the continent's leaders to put an end to decades of mismanagement and abuse of power.
At the St. Francoise Xavier Catholic Church, members of the Ephphata brotherhood -- sweating in their political T-shirts, dresses made from religious printed cloth and England football strips -- sang, danced and prayed.
"We are happy. Jesus came for the sinners. Cameroon is ill so we are happy he has come to save us," said Robert Nguidjoi, as crowds shuffled to the altar to be blessed by the priest.
The pope will also promote peace and reconciliation on a continent where violence often stems from religious quarrels but his followers face another challenge -- from the evangelical churches that have sprung up in recent years.
But his visit coincides with the developed world battling against worsening financial crises, which many fear will lead to diminishing assistance for the world's poorer nations.
"Cameroon and Africa in general could offer the pope the opportunity to present the continent's case on the international stage, in other words, champion their case," said Eric Ambono, a social sciences researcher in Yaounde, Cameroon's capital. (Additional reporting by Tansa Musa in Yaounde and Philip Pullella aboard the Papal Plane, Editing by Daniel Magnowski)
Our Standards: The Thomson Reuters Trust Principles.