The Tajik parliament has ratified an agreement with Pakistan on the mutual guarantee of investments, RFE/RL's Tajik Service reports.
Members of parliament told RFE/RL that the ratification of the document makes Pakistan eligible to participate in the Roghun hydropower station project.
Islamabad has expressed interest in participating in the project for several years.
The government in neighboring Uzbekistan opposes the project.
Russian President Dmitry Medvedev supported the Uzbek position on Roghun when meeting with Uzbek President Islam Karimov in Tashkent last week. He said all plans on the construction of new hydropower stations should be approved by all the Central Asian countries.
Dushanbe has been critical of Medvedev's statement, saying it contradicts Tajik-Russian agreements, including one on Russia's involvement in the construction of the 350-meter-tall dam on the Vakhsh river.
Landlocked Uzbekistan relies on its neighbors for water supplies and for transit routes to export its energy resources, while Tajikistan and Kyrgyzstan are the region's two major water suppliers.