MOSCOW - An agreement allowing US companies to export nuclear technology to Russia is to take effect Tuesday after the US ambassador and a deputy Russian foreign minister exchange diplomatic notes.

The civil nuclear agreement, which cleared the US Congress last month, allows the United States and Russia to exchange nuclear energy technology, engage in joint commercial nuclear power ventures and work more closely in combating nuclear proliferation.

Moscow hopes it will lead to major contracts for its nuclear industry, including projects to enrich uranium and produce uranium fuel.

U.S. Ambassador John Beyrle and Deputy Foreign Minister Sergei Ryabkov are to exchange notes activating the agreement.