The London High Court has dismissed a $1.2bn (£840m) claim against US investment bank Goldman Sachs over Libya’s sovereign wealth fund.
The Libyan Investment Authority (LIA) was looking to recoup funds it said had been lost through nine disputed trades conducted in 2008.
The Libyans said the bank had taken advantage of its lack of financial savvy, exerting "undue influence".
Goldman Sachs told the court the claims were without merit.
Dismissing the LIA allegations, the judge ruled there had been no undue influence from Goldman.
The LIA accused Goldman Sachs of encouraging it to make complex, money-losing investments with its $67bn national investment fund, set up by Col Muammar Gaddafi in 2006 to invest the country’s oil wealth.
The nine equity derivatives expired worthless.
The bank denied all the claims, saying it was a case of "buyer’s remorse".
Goldman Sachs on Friday welcomed what it described as "a comprehensive judgment in our favour".
But the LIA said it would continue to fight to "return Libya’s wealth to the people of Libya".