JOHANNESBURG -- The century-old African National Congress, which led the victory over apartheid 18 years ago and has governed South Africa since, must root out corruption and return to the values of its past, President Jacob Zuma said Tuesday.

Zuma, who leads the ANC party, also called for radical steps to speed the lifting of the country's black majority out of poverty. However, he acknowledged the global recession would make that difficult, and offered no details. The ANC remains by far the most dominant party in South Africa, but impatience among its core supporters has erupted into scattered protests in the poorest communities over lack of housing, jobs and government services such as water and electricity.

Zuma spoke at the opening of an ANC policy conference where the party hammers out stances on economic and other issues and prepares for internal leadership elections. Zuma won the last leadership elections in 2007 after an unusually public and bruising contest among ANC factions that led to a split in the party. He is expected to face a tough fight to hold onto the party presidency at the leadership conference in December. The next general election in South Africa is in 2014.

On Tuesday, Zuma called for an end to divisiveness. He quoted Nelson Mandela, the ANC leader who was South Africa's first black president, as saying unity was the rock on which the party was founded. Zuma wore a black leather jacket with the ANC logo emblazoned over his heart and addressed about 3,000 delegates.

In a speech that lasted more than an hour, Zuma called on the ANC to "cleanse itself of alien tendencies."

Among the ills, he said, were corruption, abuse of power and lack of discipline, contrasting with the party's historic values of selflessness, honesty and sacrifice. His audience responded with scattered applause.

"We should support, guide and strengthen the ANC Youth League in particular," Zuma said. And he called on other party factions not to deepen divisions.

Zuma owes his rise in part to support from the Youth League under its now ousted leader, Julius Malema.

After a lengthy disciplinary process that strained an already tense party, Malema was expelled from the ANC earlier this year for sowing disunity and failing to show remorse or willingness to accept party discipline. Malema alleges he was targeted because of his political differences with Zuma and other senior ANC members.

Malema portrays himself as the voice of an impoverished, young and restive South Africa. Critics say he's drawn too much negative publicity with racially divisive remarks and calls for nationalizing South African mining companies and seizing land from white farmers.

Addressing economic issues Tuesday, Zuma said that while white racist rule has ended, much of South Africa's economy remains controlled by whites. He said Mandela's government in 1994 had been unable to radically change the economy for fear of spooking foreign investors.

Zuma pointed to the slow pace of land reform, which includes government efforts to buy land from whites to be transferred to blacks. Under apartheid, laws barred blacks from owning property in most of South Africa.

"The current willing buyer, willing seller model must be reviewed," Zuma said, earning applause.

He did not explain, however, how he would get around legal barriers to the government simply seizing property. An ANC review of land policy released earlier this month cautioned changes should not risk "significantly disrupting agriculture production and food security."

Zuma called for "a dramatic shift, or giant leap to economic and social transformation" to combat poverty, unemployment and inequality. He said solutions tried in the past, such as giving black South Africans an opportunity to take shares in existing companies, had helped increase the number of middle class South Africans but not created new sources of wealth.

He acknowledged growth was slowing worldwide, and "many economic targets will be difficult to attain."

Sandile Zondi, a delegate to the conference from Zuma's eastern KwaZulu-Natal stronghold, said Zuma was not overstating problems within the party and the government. Zondi traced the crisis in part to the party's growth, and its attempt to embrace all classes and races in South Africa. That creates competing factions, Zondi said.

But he said the party remains strong, and would be further strengthened by "continuing to reflect and renew itself."