Banda said in an address on national television and radio that all Zambians must unite following this week's presidential election.

Patriotic Front leader Sata was declared winner in the early hours of Friday with 43 percent of the vote, while Banda got 36.1 percent of the count.

During his most recent campaign, he toned down his criticism of massive Chinese investment in the copper-rich southern African nation.

But even as he prepared to take on the tough job of leading Zambia, Banda has his work cut-out for him after the kwacha fell 2.8 percent to a 14-month-low of 5,145 against the dollar. Traders said it would remain vulnerable until he gave clearer indications on his future policies.

Analysts said Sata would almost certainly review contracts with foreign companies struck by Banda's administration, and could overhaul the country's mining, trade and banking regulations.

"Sata's upset victory will likely usher in a new era for a resource-nationalist mining sector policy," said Sebastian Spio-Garbrah, an analyst at Africa consultancy DaMina Advisors.

"Sata has said that his government will insist that foreign miners keep all their export forex revenues within the country and only repatriate profits. He has called for a new revamp of the country's mining code and a review of mining contracts signed under Banda."

Sata told Reuters last week he would maintain strong commercial and diplomatic ties with China and would not introduce a minerals windfall tax, but implied he might impose some form of capital controls to keep dollars in the country.

Sata has enjoyed a long and varied career that included stints in motor vehicle assembly plants in Britain and as a porter with British Rail before becoming a grassroots political activist under first president Kenneth Kaunda.

Sata secured support among the youth on the back of campaign promises to create jobs and his criticism that Banda's government failed to let ordinary Zambians share in the proceeds from the country's copper mines.

"We are now a relieved nation. God has finally answered our prayer," said Emmanuel Mwanza, a student at the Zambian Open University.

"We respect the Zambian people's choice, and are willing to continue to promote traditional friendship with Zambia and expand mutually beneficial cooperation in every aspect," Foreign Ministry spokesman Hong Lei told a regular briefing in Beijing.

Chinese companies have become major players in Zambia's $13 billion economy, with total investments by the end of 2010 topping $2 billion, according to data from the Chinese embassy.

But Sata has accused Chinese mining firms of creating slave labour conditions with scant regard for safety or the local culture.

Election monitors from the European Union and regional grouping the Southern African Development Community said the polls were largely fair although there was some violence.

Youths fought running battles with riot police on Thursday in the towns of Ndola and Kitwe, 250 km (150 miles) north of Lusaka, setting fire to vehicles and markets in the normally peaceful mining heartland.

Sata had strong backing in urban areas and the economic centre in the Copper Belt, while Banda, a farmer and former diplomat, relied on votes from rural areas.

1964 - Zambia, formerly the British colony of Northern Rhodesia, holds its first election. Kenneth Kaunda wins presidency and his United National Independence Party (UNIP) wins parliamentary election. In October, Zambia gains independence from Britain.

1991 - Movement for Multi-Party Democracy (MMD), led by Frederick Chiluba, secures landslide victory in first multi-party election in 23 years.

April 2001 - Nine ministers quit the MMD to protest against Chiluba's bid to run for an unconstitutional third term. Chiluba backs down.

Dec 2001 - Prominent lawyer and former Vice-President Levy Mwanawasa of the MMD wins a presidential election with less than 30 percent of vote. Street protests and legal challenges follow.

Feb 2003 - Chiluba is charged with stealing more than $2 million of public money while in office, part of a widening anti-graft drive by Mwanawasa.

May 2007 - British judge Peter Smith orders Chiluba to pay $58 million to the Zambian Treasury to compensate for money he was suspected of stealing while in office.

Nov 2008 - According to final results, Banda wins 40.1 percent of the votes cast in the October 29 election versus 38.1 percent for challenger Michael Sata.

February 2010 - Banda visits China, meeting counterpart Hu Jintao. They sign a mining cooperation pact bolstering ties between Africa's largest copper producer and its biggest single investor.

August 2011 - A court clears Banda to take part in the elections after the main opposition party sought to have him blocked on grounds that he does not qualify to stand.