Based on Angolan government statements, a report Sunday identified a man sentenced to death in Angola for espionage and smuggling as a former employe of the U.S. Consulate in Luanda. According to the State Department, the man, Angolan citizen Francisco Fragata, has had "no connection whatsoever with the United States government or any of its agencies" at any time.

Angola, struggling to rebuild an economy shattered by nine years of civil war, is backing its military campaign against antigovernment guerrillas with a concerted offensive against economic sabotage and corruption.

The message that the Marxist government intends to combat economic subversion emerged this week at the close of a six-month trial of 124 persons charged in an alleged foreign-backed plot to destabilize the Angolan economy.

Throughout the hearings, Angola's state media attacked the defendants as enemies as dangerous to the state as armed aggressors. They were accused of running a diamond and currency smuggling ring that drained Angola of $150 million in two years with the aim of provoking social and political upheaval.

In what were termed exemplary punishments, the Popular Revolutionary Tribunal in Luanda, the Angolan capital, sentenced a former U.S. consulate employe to death by firing squad for spying on behalf of the United States and playing a leading role in the smuggling operation.

According to Angolan news agency reports monitored in Lisbon, the court handed down jail sentences ranging from one to 16 years on 119 other defendants. Four others were acquitted. Fifty-six of the accused were Portuguese, 30 of whom were tried in their absence and are believed to have fled to Portugal.

State prosecutors charged that the operation was backed by "the highest financial circles in the United States and Europe," but Francisco Fragata, an Angolan who worked at the U.S. consulate in Luanda until its closure in 1977, was the only defendant directly accused of espionage.

Portuguese Foreign Minister Jaime Gama has urged Angola to commute the death sentence, Reuter reported Saturday. A spokesman for the Foreign Ministry said Gama asked that the sentence be commuted for humanitarian reasons.

The hearing, televised daily by the state network, has sought to make clear, both at home and abroad, Angola's ability to deal with corruption and attempts to undermine its economy.

Angola, with vast resources of oil and diamonds, is potentially among the richest countries in southern Africa. But since independence from Portugal in 1975, its economy has been ravaged by civil war, South African military incursions and a sabotage campaign by antigovernment guerrillas that has destroyed communications and energy installations.

Most of the country's depleted income is poured into defense, and, despite extensive Soviet military aid, the support of an estimated 25,000 Cuban troops is proving a heavy financial burden. In this climate, trial prosecutors stressed the marked setback organized corruption has dealt Angola's reconstruction efforts.

Fragata was found guilty of acting as a clandestine U.S. agent in Angola, gathering classified information, including radio ciphers, under the instruction of an alleged Lisbon-based spy for the United States named Rui Dias. According to the Angolan authorities, Dias is still at large in Portugal.

The court found that Fragata used a trip to Lisbon as captain of the Angolan national roller-hockey team to attend a briefing with Dias at the U.S. Embassy here, where he "received instructions for his criminal actions in Angola." No date was given for the meeting. The prosecution produced as evidence copies of "compromising " correspondence exchanged between Fragata and unspecified contacts in Washington.

Fragata also was convicted as a ringleader of the network that smuggled between $7 million and $8 million worth of rough diamonds a month out of Angola in 1982 and 1983. The court was told the operation involved several military officers and used pilots and other employes of the state airline TAAG as couriers.

The diamonds were smuggled to Lisbon and from there to illicit traders in Antwerp, Belgium, and New York.

The defendants were also charged with flooding the country with foreign currency and seeking to corrupt high-ranking officials of the ruling party, the Popular Movement for the Liberation of Angola, as part of an overall scheme to destabilize the country and foment counterrevolution.

The greater prominence given the corruption scandal over the spying charges in the official Angolan coverage of the trial was seen by diplomats here to reflect recent Angolan efforts to establish closer ties with the United States.

President Jose Eduardo dos Santos has said he is anxious to work with the United States toward an independence settlement for neighboring Namibia, a key source of conflict in southern Africa, and has suggested that he is prepared to show flexibility on the question of a withdrawal of Cuban troops, which the United States and South Africa want to make a condition of Namibian independence.