The Federation Council, the upper house of Russia's parliament, approved the law at its latest summer session July 11.
At a March 11 referendum, residents in southeast Siberia overwhelming voted in favor of merging the Chita Region and the Aginsk-Buryat Autonomous Area into the Trans-Baikal Territory. The unification, one of a series of similar moves in Russia recently, is expected to provide an economic boost to the region and raise local living standards.
The new region of the Russian Federation will officially be established on March 1, 2008.
"The new region will form state authority and judicial bodies by January 1, 2010," said Rafgat Altynbayev, head of the Federation Council's committee for regional policy.
President Putin supported the merger as part of the Kremlin's ongoing campaign to simplify the country's administrative-territorial divisions, and to further tighten federal control over budget spending and efficient governance in the regions.
