MOSCOW, July 5 (RIA Novosti) - Russia's new top prosecutor urged his European colleagues Wednesday to improve cooperation and prevent offenders from exploiting differences in procedural systems to their advantage.

Speaking at a Moscow conference attended by prosecutors from the 46 member states of the Council of Europe, Yury Chaika said the differences between systems meant law enforcers faced obstacles doing their jobs.

"Criminals, on the contrary, rely on their ability to hide behind those obstacles, using them as a shield, and also to hide evidence of their crimes," he said.

Chaika, who moved from this post as justice minister to become Russia's prosecutor general in late June, said prosecutors in Europe had overlooked some aspects of cooperation and urged them "to close ranks."

He also invited colleagues to study the diverse capabilities of prosecutor's offices, their powers, typical methods of identifying and curbing violations of people's rights, while he welcomed the Council of Europe's July 13, 2005 decision to transform conferences of Europe's top prosecutors into a permanent body.

"In it [the new body], we can step up efforts to consolidate the legal base of cooperation in the sphere of criminal procedure," he said.

Chaika said earlier he would be seeking to achieve a positive answer to extradition requests filed by his predecessor and turned down in London.

Russia has been seeking the extradition of tycoon Boris Berezovsky, wanted in connection with fraud and other charges, and Akhmed Zakayev, the "emissary" of Chechen militants, as well as more than a dozen other people living in self-imposed exile in the United Kingdom.