THERE are signs decades-long brotherly relations between Beijing and Pyongyang are cooling with the death of North Korean President Kim Il-sung, Chinese sources said. Beijing will make no new deals with Pyongyang, although trade talks will go on. ''Foreign trade officials have been instructed to refrain from making new deals because the North Koreans cannot afford to pay. They have owed [China] too much,'' an informed Beijing source said. China has long been pressing North Korea to change its economic policies and Chinese firms reportedly have been unwilling to export to North Korea because it has no means to pay. Chinese figures show Chinese export to North Korea totalled only US$177 million (HK$1.37 billion) in the first five months of this year, down 32 per cent on the same period last year. ''Soon after the death of the old Kim, North Korea has become one of the sensitive issues in China. It seems that Beijing has taken this chance to distance itself from Pyongyang,'' the source said. Another sign in this direction was China's recent air agreement with South Korea, he argued. China and South Korea have agreed to open new air routes, allowing South Korean aircrafts to fly from Seoul to Qingdao, Shenyang and Beijing from November. ''Before, Beijing and Shenyang were out of the question because it would mean South Korean aircraft flying too close to North Korea,'' the source said. The new air arrangement was announced last Thursday. The press officer for the South Korean consulate in Hong Kong, K. S. Seo, said talks on the air deal had been going on for two years. However, a Chinese researcher on Northeast Asian affairs contends that the friendly relations between Beijing and Pyongyang will continue as before, while Sino-South Korean links also will be strengthened. ''Yes, the economic factor has been increasingly important in the post-Cold War era, and North Korea has to adopt some measures to improve its economy,'' said a researcher on Northeast Asian affairs at the Chinese Academy of Social Sciences, Han Zhenshe. ''But economic is not the only element. And the Sino-North Korean relationship is not only important country-wise, but also region-wise. ''[New North Korean leader] Kim Jong-il has attached much importance to the Sino-North Korean relations and so has China. And a good relationship with South Korean does not mean that the friendly relations with Pyongyang cannot be maintained.'' Analysts said an important indication of bilateral ties would be how soon Mr Kim would visit China, and the reception he would get.