JOHANNESBURG - South Africa's ruling ANC celebrated a commanding lead in an election that will install Jacob Zuma as president and put him under immediate pressure to deal with a faltering economy and improve the lives of the poor.

The African National Congress held 67.2 percent of the vote according to latest results, suggesting it would keep the two-thirds majority it would need to change the constitution and further strengthen its hold, a matter of concern to markets.

Thousands of ruling party supporters danced into the night to celebrate the ANC's success in the face of the toughest opposition challenge since the end of apartheid in 1994.

Despite the failure of a party of ANC dissidents to make a dramatic impact, the ANC appeared to be just short of the nearly 70 percent of the vote it won in 2004 and to have lost control of the Western Cape province, center of the tourist industry.

Zuma, due to be sworn in early next month, will be under pressure to deliver from day one.

Zuma tapped into a dramatic change in the mood of South Africa's poor black majority. Forgotten by the elite, they have run out of patience and are now demanding the economic dividends of democratic rule, political commentator William Gumede said.

He is unlikely to have the honeymoon period enjoyed by past ANC governments. If he fails to deliver, the poor will also turn against him.

The rand currency firmed against the dollar to a new 6-1/2-month high, aided by a strong euro and as investors responded to a peaceful vote and the result as expected.

The ANC has given repeated assurances it has no plan to change the constitution even with a two-thirds majority.

You don't need two-thirds to govern a country. You need political will to do so, ANC spokeswoman Jessie Duarte said.

NEW PARTY STRUGGLES

A reinvigorated opposition had hoped to at least curb the majority to below two-thirds, but for many voters the ANC's credentials from the fight against white minority rule still outweigh its failure to tackle crime, poverty and AIDS.

The Congress of the People (COPE), formed by politicians who broke from the ruling party, had won only 7.54 percent with 80 percent of votes counted.

The ANC's closest rival was the Democratic Alliance (DA) -- led by a white woman -- with 15.33 percent. The DA pulled ahead of the ANC in the Western Cape province, which is currently controlled by the ANC.

We've got to realign politics in South Africa and that's what I'm going to spend the next five years doing, DA leader Helen Zille said.

The 67-year-old Zuma will become president only three weeks after managing to get prosecutors to drop an eight-year-old corruption case on a technicality. His supporters dismiss the accusations against him as politically motivated.

Some foreign investors are less enthusiastic about Zuma, fearing trade union allies will push him to the left. The continent's biggest economy may already be in recession for the first time in 17 years.

In order to deal with the impact of the recession they will have to be a more effective government than the ANC has been in the past, said Steven Friedman, Director at the Center for the Study of Democracy.

Zuma has repeatedly said there will be no nasty surprises in store for investors and his room for policy maneuver is limited because of the global downturn. Finance Minister Trevor Manuel, a market favorite, is expected to stay for now.

Zuma has also pledged to tackle violent crime which could mar next year's hosting of the soccer World Cup.

Election officials estimated the turnout at 76 percent, the same as in 2004. Observers from the 15-nation Southern African Development Community and African Union said on Friday the election was free and fair.

Jacob zuma South Africa