More than 6,600 kilometers of new rail lines will be built in China this year, a leading railway official said here on Thursday. About 630 billion yuan (103.11 billion U.S. dollars) will be allocated as fixed assets investment in the rail sector. The new railways will be mainly in the country's underdeveloped central and western regions, said Sheng Guangzu, general manager of the China Railway Corporation (CRC), at an annual work meeting. CRC has speeded up railway construction since its establishment in March. A total of 49 railway projects have started to be built, with 663.8 billion yuan of fixed assets investment, and 5,586 kilometers of new lines were put into operation. By the end of 2013, China's railways in operation exceeded 100,000 kilometers, with 10 percent for high-speed trains. Sheng added that more private capital was welcome in railway construction.