A former British special forces operative who allegedly led a foiled coup plot in oil-rich Equatorial Guinea (search) was convicted Friday of trying to buy weapons from Zimbabwe's state arms manufacturer.

Sixty-six other suspected mercenaries were acquitted of the charge in connection to a deal that officials initially said aimed to get weapons for the planned coup plot, though the judge did not link them in his ruling Friday.

The convicted suspect, Simon Mann (search) — an alumnus of the exclusive boarding school Eton (search), a former British special forces member, and a one-time movie actor — admitted trying to weapons from the Zimbabwe Defense Industries, an offense punishable by up to 10 years in prison.

Mann, however, contended the weapons, which included assault rifles, grenades, anti-tank rocket launchers and other arms, were for a job protecting a mining operation in war-torn eastern Congo.

Nineteen people, including a number of South Africans, are on trial in the West African nation of Equatorial Guinea for the alleged coup plot.

Officials say the country's Spanish-based rebel leader, Severo Moto, offered the mercenaries $1.8 million and oil rights to overthrow President Teodoro Obiang Nguema (search).

Equatorial Guinea prosecutors said Friday that they were also seeking to extradite Mark Thatcher (search), son of former British Prime Minister Margaret Thatcher (search), who is under house arrest in South Africa for allegedly providing financing for the plot.

The chief magistrate in the trial of Mann and the others in Zimbabwe mentioned no link between the attempted arms purchase and the coup plot. Magistrate Mishrod Guvamombe said Zimbabwean prosecutors failed to prove their case against Mann's 66 co-defendants.

Sixty-four of the men were arrested when their Boeing 727 landed at Harare International Airport on March 7, while two others were already in Zimbabwe with Mann at the time, allegedly to inspect the weapons.

Those 64, as well as three crewmembers, have pleaded pleaded guilty to immigration and aviation violations carrying a maximum penalty of two years in jail and a fine.

Most of the defendants have South African citizenship.

Mann was acquitted of an additional charge of taking possession of the weapons.

Equatorial Guinea, on the Gulf of Guinea, is the continent's third-largest oil producer. Its president, Nguema, has presided for 25 years over what is widely considered one of the world's most corrupt and oppressive regimes.

A lawyer for the government, Lucie Bourthoumieux, said Friday that Equatorial Guinea has "strong hopes" of winning the extradition of Thatcher, who was arrested Wednesday.

"South Africa is cooperating, and they are willing to fight furiously against all mercenaryism and terrorism," Bourthoumieux said.

However, South African officials said they had received no extradition request from Equatorial Guinea. There is no extradition treaty between the two countries.

The Equatorial Guinea government said it has not issued an arrest warrant for Thatcher — among the usual first steps toward an extradition.

The U.S. State Department and international rights groups accuse Equatorial Guinea of routine torture in prison and other rights abuses under Obiang.

Another coup suspect who had been facing trial in Equatorial Guinea, a German man, died in custody after what Amnesty International (search) said was torture.

Thatcher's spokesman Lord Bell told British Broadcasting Corp. radio that Thatcher's name had been dragged into the Equatorial Guinea affair because of "guilt by association."

Thatcher and Mann were friends, "but it doesn't follow that because you are friends with someone you are necessarily involved in what they are doing," Bell said, asserting that no documentary evidence shows Thatcher had invested in Mann's business ventures.

Mark Thatcher, a former race-car driver, has had legal problems before.

He moved to Dallas in April 1984 after a controversy over reports he represented a British construction firm that won a $600 million contract in Oman while his mother was there on a trade-boosting trip in 1981.

While in Texas, he settled a civil racketeering lawsuit for an undisclosed sum. He also faced charges from the Internal Revenue Service over his role with a Dallas-based home security company that went bankrupt.

Thatcher was scrutinized by Britain's Parliament in 1994 over reports that he was involved in arms sales to Saudi Arabia and Iraq while his mother was prime minister. He moved his family to South Africa in 1995 after business troubles in the United States.