China Railway Corp released six tender notices for bullet trains worth nearly 66 billion yuan ($10.6 billion) in all, news portal caixin.com reported on Thursday.

The total size of the deal makes it the largest yet for China Railway, the national railway operator that was created after the Ministry of Railways was dissolved in March 2013.

China Railway will purchase 98 bullet trains with a speed of 250 kilometers per hour (km/h) and 208 bullet trains with a speed of 350 km/h. The company is also seeking to buy bullet trains that can withstand extremely low temperatures.

CRRC Corp, the country's largest bullet train maker, which was formed on June 1 with the merger of State-owned train builders CSR Corp and China CNR, will enter the bidding. It will be CRRC's first bid since it was established.

China is accelerating the construction of high-speed railways. The nation has the world's largest high-speed train network, with 16,000 kilometers of track at the end of 2014.

Another 2,000 kilometers will be constructed this year, media reports said in January.