"The prosecutor requested today that the jury be dismissed," a defense lawyer, Ruslan Koblev, said.
Anatoly Chubais, the chief executive of Russia's electricity monopoly, UES, was attacked in March 2005 outside Moscow when his car came under fire. He was not injured.
Koblev said that prosecutors justified their request to dismiss the jury on the grounds that some media sources have been publishing information on the court's actions, even though the case is being tried behind closed doors.
He added that media sources were referring in their articles to Andrei Shugayev, a lawyer for Chubais.
"This is a staged action, together with the court," Koblev said. "There is only one aim, which is to dismiss the jury under any artificially created pretext available. They [prosecutors] believe that the jury may be ready to pass a not-guilty verdict."
But he also said that the prosecutors' move may be tied to the arrest of the fourth suspect in the case, Ivan Mironov, who was on the Federal wanted list for a long time and was finally detained Monday.
According to prosecutors, the suspects were motivated by their extremist views and a violent dislike of Chubais, an architect of economic reforms in the 1990s that impoverished millions and gave vast fortunes to a handful of well-connected oligarchs.
Chubais is now behind a series of unpopular decisions to hike electricity tariffs.
Three other suspects in the case - two former officers of the Airborne Troops and one former officer of the General Staff - are already on trial by jury.
Mironov was arrested Monday together with his father, Boris Mironov, a suspect in a separate inquiry into the incitement of inter-ethnic hatred.
A former head of the Russian Print Media Committee, Boris Mironov, is accused of making anti-Semitic speeches in 2003 while running for governor of Siberia's Novosibirsk Region.
