A train arrives at a station in Sichuan province, December 12, 2014.[Photo/IC]

The Beijing-Shanghai high-speed railway, the darling of the country's top operator China Railway Corp, earned 23.4 billion yuan ($3.5 billion) last year, with a net profit of nearly 6.6 billion yuan, the National Business Daily reported on Tuesday.

Net assets of the company's subsidiary that runs the route reached 131.2 billion yuan by the end of 2015, and the debt-to-assets ratio stood at 27.7 percent, the newspaper cited a report released by one of its shareholders.

Although Beijing-Shanghai High-Speed Railway Co Ltd has been vague about its financial performance, industry insiders say it's the only bullet train route in China that made money in the past five years.

The railway carried more than 24 million passengers in just half a year after it started operation in June 2011. In 2015 alone, the number reached nearly 130 million, according to the newspaper citing official statistics.

That means each passenger contributed about 50 yuan to its profit last year, it said.

Analysts said the subsidiary, as the single highest-quality asset of China Railway, is likely to seek initial public offering in the domestic market.

According to media reports, construction of a new high-speed rail connecting Beijing and Shanghai might be in the pipeline in view of the surging number of passengers along the route.

But analysts have dismissed the rumor, saying no exact words related to the plan are seen in the country's 13th Five-Year Plan (2016-30) or the Mid-Term and Long-term Railway Network Development Program during that period.