Federal prosecutors in Brooklyn say Barrack, the 75-year-old former chairman of the firm now known as DigitalBridge Group Inc, worked for the United Arab Emirates to influence Trump's campaign and administration between 2016 and 2018 and advance the Middle Eastern country's interests.
Barrack, who chaired Trump's inauguration committee, has pleaded not guilty, as has his former assistant and co-defendant Matthew Grimes.
They intend to argue that their interactions with UAE officials were part of their work for DigitalBridge, then known as Colony Capital.
Another co-defendant, Emirati businessman Rashid Al Malik, is at large.
U.S. District Judge Brian Cogan will question dozens of potential jurors to assess whether they might be biased against Barrack because of his ties to Trump, among other conflicts that could prevent them from serving.
After hundreds of potential jurors filled out questionnaires, Cogan wrote on Sept. 2 that candidates who expressed "merely some dislike" of Trump could still serve.
The trial is expected to focus on allegations that UAE officials gave Barrack input about what to say in television interviews, what then-candidate Trump should say in a 2016 energy policy speech, and who should be appointed ambassador to Abu Dhabi.
Prosecutors have said Barrack, Grimes and Al Malik never told the U.S. attorney general they were acting as UAE agents as required under federal law.
Barrack's lawyers have said the U.S. State Department, and Trump himself, knew of his contacts with Middle East officials, showing that Barrack did not intend to be a foreign agent.
(Reporting by Luc Cohen in New York; editing by Jonathan Oatis)
By Luc Cohen