South Africa's main opposition party, the Democratic Alliance (DA), says it has agreed a deal with the governing African National Congress (ANC) to form a government of national unity.

This comes after weeks of speculation about who the ANC would partner with after losing its parliamentary majority for the first time in 30 years, in last month's elections.

It got 40% of the vote, while the DA came second with 22%.

This paves the way for ANC leader Cyril Ramaphosa to remain president.

An alliance between the DA, a centre-right party, and the ANC, is unprecedented as the two parties have been rivals for decades.

Despite the bitter history, DA leader John Steenhuisen said the deal was a "new chapter in our history".

The deal will also include the Inkatha Freedom Party (IFP), a conservative party with a strong Zulu base, which got 4% of the vote.

South African news website News24 says the agreement covers the division of posts in the government, as well as the provincial governments in Gauteng and KwaZulu-Natal.

Mr Steenhuisen said: "Through the votes the country has made it clear that they do not want one party to dominate our society."

The coalition deal is likely to be welcomed by the business sector, who think it will guarantee economic stability and avoid capital flight as it leaves out two radical parties that advocate nationalisation of land, mines and banks.

The ANC's deal with the DA and IFP is also seen as an attempt to promote racial and ethnic reconciliation following a bruising election campaign.

President Ramaphosa has previously accused the DA - which draws its support mainly from racial minorities - of being "treasonous" and "reactionary".

But the deal with the DA will be unpopular among many ANC activists.