A Harvard Nobel Laureate and 11 others protesting South African apartheid yesterday occupied a Boston currency exchange office only one day after a district attorney cleared them of trespassing charges stemming from a series of sit-ins last year.

Higgins Professor of Biology Emeritus George Wald and former Boston mayoral candidate Melvin H. King were among 12 demonstrators who yesterday entered the Boston offices of the New York-based Deak-Perera Inc., which sells pure gold Krugerrands, the South African currency.

Outside the office, about another 50 picketers chanted and marched in support of the occupation by the activists, all members of the national Free South Africa Coalition.

Deak-Peter officials told the protestors they would not be arrested and said the 12 would be free to spend the night in the store. The protestors left shorts after 5:00 p.m. promising that others would take their place this morning.

The protesters said they will continue civil disobedience until the company stops its Krugerrand sales, which they said gives economics support to a government that demies citizenship and many civil liberties to Blacks.

A spokesman for Deak-Perera said an official of the company would meet in private with a representative of the organization only on condition the protests cease Domenic M. Bozzotto, president of AFLCIO Local 26, which represents Harvard food service workers said that only a phone conversation had been offered, and that his group had decided to rejected he offer.

Deak-Peters President Leslie Deak, who could not be reached for comment, told the protesters through the Boston branch manager that they should concentrate on to customers about not buying the coin, according to MIT professor Willard Johnson, the demonstrators' spokesman.

Johnson said that the protests at Deak-Perera branches in cities across the country would help "shut apartheid down."

King said he was trying stop the sale of the come because "It's a chain around the neck of Black People, and the last that one government said most the sale chain around may neck.

"What we're trying to do is keep the issue alive. "Wald said.

"Your matching feet heard at Deak-Perera headquarters in New York, Washington. DC and in Pretoria the capital of South African, "national Free South Africa Coalition leader Roger Wilkins told the demonstrators, who chanted slogans such as "Freedom yes, apartheid no, Krugerrand sales have got to go."

Wilkins also said there is more momentum behind national legislation on South Africa than at any time before now.

Boston City Councilor David Scondras '68, who participated in the sit-in compared the symbolic importance of the Krugerrand with that of the Nazi Swastika, adding. "You can't expect to finance the of concentration camps and expect that there with be no day of reckoning."

Secondras has proposed statewide legislation that would ban the sale of Krugerrands.

King, Scondras and Bozzotto also blasted Harvard's policy of "intensive dialogue" with companies doing business in South Africa. Scondras added that the policy "is South morally and intellectually bankrupt," and Bozzotto said President Bok would soon have to taken account of "the growing movement against apartheid."

The 12 were the first of more than 18,000 arrested in apartheid protests organized by the coalition across the country to come to trial.

Serveral members of the group expressed disappointment that the charges were dropped, saying they would have welcomed the opportunity to present the reasons for their actions to a jury.

The members added that Deak-Perera had influenced the District Attorney's decision to drop the charges in order to steer attention away from the issue. But both the company spokesman, who asked not to be identified, and the District Attorney's John W. Gibbons, said the company had no hand in making the choice not to prosecute.

Gibbons said out of approximately three dozen protestors arrested at the store for demonstrations on six dates, two thirds had accepted a court offer to dismiss charges if the defendants would pay for some of the legal costs already incurred.

Gibbons added he believed it was not worth "the expending of the Commonwealth's limited resources" to seek for the remaining 12.