Mehmet Hakan Atilla was convicted on five of the six counts he faced, including charges pertaining to bank fraud and conspiracy to violate US sanctions law. He was found not guilty on a money laundering charge. US District Judge Richard Berman at the federal court in New York said that Atilla would be sentenced on April 11.

The jury found that Atilla had operated a complex scheme in which Iran traded its oil and gas for gold, with some of the revenue being moved through US financial institutions without their knowledge.

"Foreign banks and bankers have a choice: you can choose willfully to help Iran and other sanctioned nations evade US law, or you can choose to be part of the international banking community transacting in US dollars," Joon Kim, the acting US attorney in Manhattan, said in a statement after the verdict. "But you can't do both."

After the Iranian hostage crisis, in which 52 Americans were held captive from 1979 to 1981, the US imposed sanctions on virtually all US financial dealings with Iran, including many bank transactions.

Links to the highest echelons of the Turkish government

Prosecutors accused Atilla, an executive at Turkey's majority state-owned Halkbank,of conspiring with Turkish-Iranian gold trader Reza Zarrab and others to help Iran escape sanctions by using fraudulent gold and food transactions.

Zarrab, the prosecution's star witness, admitted to running the deals with Iran and testified that 
he had paid over $50 million (€43 million) in bribes to Turkey's finance minister in 2012 to help advance the scheme, adding that he believed Turkish President Recep Tayyip Erdogan knew about the plot.

Erdogan has dismissed the case as a politically motivated attack on his government. A Turkish government official rejected the verdict.

"We consider this verdict void in every sense; international law has been violated," an official who declined to be named told the Reuters news agency. "It cannot have a negative impact on the Turkish economy, banking system or Halkbank, specifically."

"Our greatest wish is that this conviction, which in this form is a perversion of justice, will be corrected," Turkey's Foreign Ministry said in a statement.

The case had gained major traction in Turkey not only of its collusion claims but also because of Reza Zarrab's marriage to one of the country's most celebrated singers, Ebru Gundes.

Legal expert Ugur Poyraz told DW that  Atilla could also plead guilty and agree to cooperate with prosecutors in a bid to reduce his punishment, as Zarrab did in November.

"For example, it is possible for him to think like that: 'If I had shared some information about certain issues, I would have got a reduced sentence or even impunity. Then why don't I share these information with the prosecutors or the court now and escape with a reduced sentence?"

Turkey accuses Gulenists of plot

Ankara has said that followers of US-based cleric Fethullah Gulen were behind the Turkish investigation and the US case. They have also accused Gulen, an erstwhile ally of Erdogan's, of being the main instigator behind the 2016 failed coup in Turkey. Gulen has denied all accusations and remains in self-imposed exile in the US-state of Pennsylvania as Turkey continues to seek his extradition.

Before the trial, Erdogan had reportedly pressed US President Donald Trump to quell the investigation and strongly criticized Washington, calling the case a "plot" aimed at hurting Turkey.

Turkey rejects the verdicts

Turkey's deputy Prime Minister Bekir Bozdag took to Twitter to describe the trial as a "political conspiracy" in which the verdict had "been delivered before hearings even started."

Bozdag added in another tweet that he wasn't surprised about the verdict and that it was of "no legal value to Turkey."

Turkish President Recep Tayyip Erdogan's spokesman Ibrahim Kalin meanwhile said "this is a scandalous verdict in a scandalous trial."

Halkbank also issued a statement, distancing itself from the trial:

"As well as our bank not being a party to the trial, no administrative or financial decision has been taken against our bank," it said, adding that the all of the bank's transactions were "transparent" and "always in compliance with universally valid and international standards."

Appeals expected

Victor Rocco, one of Atilla's lawyers, said the banker would appeal the verdict if it is not overturned by District Judge Berman.

"We believe he's innocent," Rocco said. "We intend, and he intends, most importantly, to continue to fight and clear his name."

During the trial, Rocco said his client had been a "hapless and helpless pawn" caught up in a conspiracy that had been created by his boss at Halkbank and Zarrab. "There's something bigger going on here," he said. "There's something going on I don't understand."

"He understands it's only round one," said another defense lawyer in the case, Cathy Fleming.

ss,jbh/rt (Reuters, AP, AFP, dpa)