MOSCOW, July 18 (Xinhua) -- Russian President Vladimir Putin has appointed Valentin Sobolev as acting Security Council head following his approval of Igor Ivanov's resignation, the Kremlin press service said Wednesday.

    Putin issued a decree appointing Deputy Security Council Secretary Valentin Sobolev as the new head of the council, and a decree accepting the letter of resignation, which Ivanov tendered in early July, a statement posted on the Kremlin's Web site said.

    "Ivanov began speaking about his plans to step down several months ago. He handed in his letter of resignation two weeks ago," Interfax news agency quoted a source as saying.

    The source said there were no plans to restructure the Security Council, and made no comment on the future plans of Ivanov, a former foreign minister.

    Russian media reports earlier suggested Ivanov could be named ambassador to a European country, or leave the civil service for academia, whereas others said he could become another candidate to succeed Vladimir Putin, whose presidential term expires in 2008. But Ivanov said Wednesday he was not going to get involved in politics and was considering a career in academia.

    "I have a doctorate degree in history, and I am planning to devote most of my time to teaching and scientific research," Ivanov was quoted by the RIA Novosti news agency as saying Wednesday.

    Sobolev, 60, who spent most of his career in Russia's state security apparatus, is considered "a man on the president's team."

    "He is a serious professional, a team player, who has spent many years in this (state security) sphere," the RIA Novosti news agency quoted an anonymous Kremlin source as saying.

    Russia's Security Council was established on June 3, 1992, and is chaired by the Russian president. Sobolev has been deputy head of the Security Council since 1999.

    Since 1972 Sobolev has held various positions at the KGB, the Security Ministry, the Federal Counter-Intelligence Service and the Federal Security Service.

    In 1994 he was appointed deputy director of the Federal Counter-Intelligence Service, in 1997 first deputy director of the Federal Security Service and in 1999 deputy secretary of the Security Council.