Soviet President Leonid Brezhnev will pay an official visit to India in December, official Indian sources said. The visit will be his first since 1973. India's planning minister is now in Moscow preparing for Indo-Soviet talks in New Delhi next month. There, too, is the chairman of India's Atomic Energy Commission, who is discussing nuclear cooperation, according to Indian news agencies. A doubling of Soviet exports of crude oil, kerosene, and diesel to 5 million tons a year has also been suggested. India would also export 500,000 tons of rice and 200,000 tons of potatoes over the next three years, with more if needed.