Klebnikov, a U.S. citizen, was killed in Moscow on 9 July 2004 as he was leaving work.
Two ethnic Chechens, Kazbek Dukuzov and Musa Vakhaev, were detained later that year in connection with the murder. They will be tried as part of a criminal group accused of extortion and carrying out murders-for-hire.
Dukuzov is also accused of involvement in the June 2004 murder of former Chechen Deputy Prime Minister Yan Sergunin, as well as the attempted murder of former Yukos official Aleksei Pichugin.
Four other suspects in the Khlebnikov murder (Khozh-Akhmed Nukhaev, Magomed Edilsultanov, Magomed Dukuzov, and Marat Valaev) have been put on the international wanted list.
The preliminary hearing will be used in part to determine whether the trial will be by jury or judge.
(Interfax/ITAR-TASS)