An Indian analyst suggested Friday that India and China open more border crossings for trade to strengthen economic ties between the two countries. Senior Indian journalist, columnist and author Sunanda K. Datta- Ray made the appeal in an article published by the Asian Age daily on his latest trip to the Indian state of Sikkim bordering China\' s Tibet Autonomous Region. \"It must be nearly 40 years since I made my way to Nathu-la, the pass at 14,400 feet (4,389 meters) that is supposed to be one of the three Himalayan trade routes between India and China,\" he said. \"It was a different world. Sikkim was a monarchy then and India and China bitterly critical of each other.\" Ray described how traditionally trade between Sikkim and China\' s Tibet Autonomous Region was conducted along 13 routes. But these were all closed after the 1962 border war between India and China. He said things began to look up in 1991 when two new markets were set up at Sherathang in Sikkim and Rinqingang in China under the 1991 Sino-Indian memorandum of understanding. The number of items both on the import and export list from Sikkim were increased resulting from trade between Sikkim and China. Ray said that even though two other passes along the India- China border, Gunji in Uttarakahnd and Shipki in Himachal Pradesh, were opened, the total trade on the border areas is an infinitesimal fraction of the 66 billion U.S. dollar bilateral trade. Ray concluded that not only should these three passes be kept open, the remaining trade passes between India and China should be reopened as well and \"administered imaginatively on both sides of the border to encourage the human contact that is now sadly absent from Sino-Indian relations\".