Lisbon – Portugal said on Monday it regretted a decision by South Africa to expel its ambassador over the leaking of a misdirected note from President Nelson Mandela to Indonesian President Suharto.

"The South African authorities, alleging a misunderstanding between the Portuguese embassy and the South African presidency, last Friday (August 1) requested the departure from Pretoria of Ambassador Vasco Valente," a Foreign Ministry statement said.

"The ambassador, who had been due to leave Pretoria at the end of August, returned to Lisbon the next day," it added, saying Portugal regretted the decision.

South African government sources had earlier confirmed that the ambassador had been given 48 hours to leave.

It was the first time South Africa had expelled a diplomat since Mandela became the its first democratically elected leader in 1994.

The sources said Mandela had written to Suharto in mid-July, asking him to release East Timorese rebel leader Xanana Gusmao as a first step towards resolving the conflict there.

The letter was sent in error to the embassy of Portugal, East Timor's former colonial power, and was neither returned nor forwarded to the Indonesian embassy.

Mandela's proposal was leaked to newspapers in Portugal before Suharto was made aware of it and the incident bruised his attempt to bolster a United Nations effort to resolve the conflict over Indonesia's disputed rule in East Timor.

The South African sources said the incident had not permanently damaged relations with Indonesia or Portugal.

Mandela, whose own release after 27 years in jail opened the way in 1990 to a peaceful settlement in South Africa four years later, met Gusmao during a recent visit to Indonesia.

He has since invited Suharto to visit South Africa in November, following a proposed visit by East Timorese bishop and Nobel peace laureate Ximenes Belo in October.