But the union said it would continue to advise its members not to perform in South Africa because its sister union there, POWE, was not recognised by the theatres and was unable to provide proper financial and contractual protection.
Equity's ban on programme sales was introduced in 1976 because of fears that South African broadcasters would discriminate against black and Asian actors by refusing to buy programmes in which they featured. It was thought this could influence British casting directors against choosing such actors.
The boycott was supported by Glenda Jackson, the actress, who said it should stay 'until the South African regime was dismantled in deed rather than words'. But the veteran actor Marius Goring, who unsuccessfully took Equity to court over the decision, has argued cultural infiltration would be a more effective anti-apartheid weapon.
Last Friday, 5,264 of Equity's 43,000 members voted to lift the ban and 1,735 voted against. Ian McGarry, general secretary, said the numbers were 'representative'.
Agreements with the BBC, ITV, independent producers and advertising agencies would still have to be reworked to implement the new policy, Mr McGarry said.
The union expects South Africa to be particularly keen on educational, drama, situation comedy and children's programmes and says the market could rival Australia - which has also lifted an identical ban on programme sales to South Africa - as an outlet for British programme sales. Viewers are said to be desperate for a change from their constant diet of often-violent American imports.
In 1990 Channel 4 was said by Equity to have breached the boycott by selling Brookside to Bophuthatswana, which C4 had not regarded as part of South Africa. Other breaches have allegedly included the sale of How Green Was My Valley, the BBC drama serial, sold by a distributor.
'The changes in South Africa in recent months are the reason why the issue was put back to a referendum,' Mr McGarry said. He added that the board of the South African Broadcasting Corporation used to be appointed by the South African government and was answerable to it. 'The new board is broadly representative of the inter-racial community . . . and is recognised as such by the ANC and POWE.'
Further support for the referendum, which follows others in 1991 and 1986, came after Nelson Mandela this year agreed that the ban should be lifted.
Yesterday theatre companies said Equity's stance against tours should also be reviewed. The policy prevented the English Shakespeare Company from touring townships with its multi-cultural production of Macbeth last year.
An ESC spokeswoman said: 'Equity should support people who want to perform in South Africa. It's as if the English cultural establishment are happy to have exciting tours from South Africa but we are not allowed to go there in return.'
Adrian Noble, the artistic director of the Royal Shakespeare Company, said: 'For Equity to be so moralistic about this after Nelson Mandela has toured the world encouraging people to open their doors to South Africa seems to me pompous and small-minded.'