FORT MEADE, Maryland (Reuters) - The founder of the WikiLeaks website, at the center of the trial of a soldier charged with the biggest U.S. leak of classified material, solicited secret military information during a 2009 conference in Berlin, a Marine Corps computer security expert testified on Tuesday.

On the witness stand at the court-martial of Private First Class Bradley Manning, Staff Sergeant Matthew Hosburgh said he attended the 2009 computer security conference to update himself on potential threats to U.S. data networks, which he helped manage.

Wikileaks founder Julian Assange's one-hour lecture at the conference included an appeal for secret military information, Hosburgh said.

"Not only classified information, but also trade secrets and anything of that nature," he testified.

Prosecutors also presented allegations on Tuesday that information downloaded by Manning and emailed to Wikileaks reported on U.S. military weapons systems, their vulnerabilities, troop movements and combat tactics.

Manning, 25, is accused of providing more than 700,000 secret files to WikiLeaks, an anti-secrecy website, while serving in Iraq in 2009 and 2010.

Assange has taken refuge in the Ecuadorean Embassy in London for the past year as he faces criminal sexual charges in Sweden. Assange, an Australian, says the charges are reprisal for Wikileaks publishing information embarrassing to the U.S. and other governments.

The 21 charges against Manning, including aiding the enemy, could lead to life imprisonment without parole if he is convicted.

His trial coincides with the unauthorized release last week of information by a former National Security Agency contractor of widespread government telephone and Internet usage surveillance of private U.S. citizens not suspected of crimes.

(Reporting by Ian Simpson; Editing by Ellen Wulfhorst, Bernard Orr)

[U.S. Army Private First Class Bradley Manning departs the courtroom after day four of his court martial at Fort Meade]