“He was not able to meet me here in Stockholm. He proposed a meeting on July 22nd in Brussels… (I want to) find out what he knows about the Holbrooke agreement,” Karadzic’s lawyer Peter Robinson told AFP.
He was referring to a deal rumoured to have made between Karadzic and top US diplomat Richard Holbrooke, who was the US peace negotiator in Bosnia.
The former Bosnian Serb wartime leader, 64, claims he agreed in July 1996 to step down from public life in return for immunity from prosecution.
Holbrooke has insisted that no such deal was made.
Bildt, who served as a European Union mediator during the Balkans conflict, has also previously rejected any notion that an agreement was struck with Karadzic.
“Such a deal never existed. There has not been any attempt to drop the charges,” he told Swedish public radio in August 2008.
The tribunal ruled in December that the alleged immunity deal, if it existed, would be invalid and could not stop the trial.
Karadzic was arrested on a Belgrade bus last July, 13 years after he was first indicted for war crimes.
He faces 11 charges, notably for the 44-month siege of Sarajevo that left 10,000 dead and the July 1995 massacre of around 8,000 Muslim men and boys in Srebrenica.
Karadzic denies all the charges. His trial is not expected to start until September.