United Russia on Monday presented three candidates for the governorship of Kemerovo, giving President Dmitry Medvedev the option of reappointing the veteran incumbent for a fourth term.

Medvedev said in December that regional bosses should not govern more than three terms, and he has recently replaced a string of long-serving governors with younger candidates.

Duma Speaker Boris Gryzlov, who chairs United Russia's executive council, told Medvedev that the three candidates were "of equal worth," the Kremlin said in a statement on its web site.

United Russia's list includes incumbent Governor Aman Tuleyev, who has run the country's biggest coal mining area since 1997. The other two candidates are Tuleyev's first deputy Valentin Mazikin and State Duma Deputy Sergei Neverov, the Kremlin statement said.

Tuleyev was a Communist presidential candidate in the 1990s and switched allegiances to United Russia only after 2000. He is regarded as enormously popular in the region while having an iron hold over his administration.

If reappointed, Tuleyev, 65, would receive a fourth five-year term.

Gryzlov described Mazikin as being a United Russia supporter, while Neverov is a member and the party's top official for Siberia.

Meanwhile, former State Duma Deputy Natalya Komarova took up her job both as governor and head of the government in the Khanty-Mansiisk region, Interfax reported Monday. Komarova replaced Alexander Filipenko, who governed the oil-rich area east of the Urals for 20 years.

Also Monday, the Kursk regional legislature confirmed Alexander Mikhailov for his third term as governor, Interfax reported.