The South African government today abandoned restrictions on Winnie Mandela, wife of imprisoned black nationalist leader Nelson Mandela, ending 24 years of almost continuous confinement.

In another major development, Bishop Desmond Tutu, the 1984 Nobel peace laureate, joined the call for economic sanctions against South Africa, saying he had "no hope" that the white-minority government would dismantle the apartheid system of segregation unless forced.

The end of the restrictions on Mandela follows a test-case judgment in South Africa's highest court, the Appeal Court, two weeks ago that has thrown the government's controversial system of bannings and detentions without trial into disarray.

Moments after officials told Mandela's lawyers that they were abandoning the restrictions on her, the black nationalist leader's wife headed for her family home in Soweto from which the latest order, issued in December, had banned her.

She was given a triumphant welcome by relatives and a crowd of neighbors and passersby, who quickly gathered at the little three-room, red-brick bungalow where Mandela is now living legally for the first time in 10 years.

Mandela, whose long defiance of the authorities has made her a major symbol of resistance to South African blacks, made no display of satisfaction, declaring that "there can be no particular excitement while our people are suffering so much oppression."

[State Department spokesman Bernard Kalb said the United States "would obviously be pleased that Mrs. Mandela's ban is lifted. We have long opposed banning any person for his or her political beliefs."]

The Appeal Court judgment two weeks ago declared 14 orders for detention without charges to be invalid because the minister of law and order, Louis le Grange, had failed to state his reasons for issuing them.

Le Grange merely had stated that in his opinion the detentions were necessary "in the interests of the security of the state," as has been the government's practice since the system was introduced 34 years ago.

It was the first time detention orders had been invalidated by the courts. Immediately after the judgment, five appeals were lodged on similar grounds by people under "banning orders."

The orders limit an individual's movements in a variety of ways. They prohibit banned persons from being quoted in the media, usually prevent them from being in the company of more than one other person at a time and sometimes banish them to remote areas or place them under house arrest.

Mandela has been under all these forms of restriction during the past 24 years.

Le Grange, acknowledging that the judgment meant that those five orders were also invalid, withdrew them, including one against a white lawyer, Roley Arenstein, who had been banned almost continuously since 1953.

Mandela's case is slightly different. She challenged her banning order last December, lost the case in the Transvaal provincial Supreme Court, but gave notice that she intended to appeal.

Her lawyers began the appeal process yesterday, and today officials told them the state was abandoning its opposition to the case, meaning it acknowledged that her banning order was also invalid.

There are now only five persons still under banning orders and these are likely to be freed soon as well.

There is speculation that le Grange may issue rewritten banning orders to comply with the judgment, but legal experts point out that if he gives detailed reasons for issuing the orders, as the judgment requires, he may be challenged on the facts, resulting in further court actions.

Alternatively, the government may amend the law to make reasons unnecessary, the experts say.

This is only the second time Mandela's restrictions have been lifted since she was first banned after her husband was imprisoned for life 24 years ago for plotting the overthrow of white-minority rule.

Her banning order expired briefly in 1976 after she was released from a six-month prison sentence for violating it. It was then renewed in even more severe form. For the next nine years, Mandela was banished to a remote country village.

This restriction was lifted last December when a new order was issued allowing Mandela more freedom but prohibiting her from entering the Johannesburg area, where her home is.

The media still may not quote Mandela because the government long ago declared her a "listed person" under another security law. She still will be unable to address meetings because of a new decree that came into force today prohibiting all unauthorized meetings for a year.

Asked at a brief press conference at her house today whether she believed her husband might join her there before the end of this year, Mandela discounted recent speculation that the government was considering releasing him.

"It is quite obvious now that the government never had any intention of releasing him and the other political prisoners," she said. "It was merely strategizing."

Bishop Tutu, who is the Anglican bishop of Johannesburg, said at a press conference today that he had decided to call for economic sanctions after 10 years of fruitless attempts to persuade the government to relinquish white domination.

"Nothing [President Pieter W.] Botha has said has made me believe he and his government are serious about dismantling apartheid," Tutu said. "We face a catastrophe in this land, and only the action of the international community by applying pressure can save us."

"Our children are dying. Our land is burning and bleeding, and so I call on the international community to apply punitive sanctions against this government to help us establish a new South Africa, nonracial, democratic, participatory and just. This is a nonviolent strategy to help us do so," Tutu went on.

Tutu said he was not directing his appeal to President Reagan or British Prime Minister Margaret Thatcher. "I put my hopes on the young, especially at the American universities, to exert the pressure," he said.

[In Washington, State Department spokesman Kalb said, "The United States does not believe that punitive sanctions will help promote change in South Africa . . . . In the U.S. view, punitive sanctions would hurt South Africa's economy, which is central to the region's stability and a major force for change domestically. Secondly, they won't be effective in ending apartheid and could escalate the level of violence and polarization within the country."]

Tutu said arguments that sanctions would hurt blacks more than whites were hypocritical. It was remarkable that "those most vehement in their concern for blacks have been whites," he said, while two recent surveys showed more than 70 percent of blacks supported sanctions.

The Nobel laureate faces possible arrest under the security laws, which make it treasonable to undermine the country's economy.