Shares of China Railway Group, the country's second-largest railway builder, tumbled yesterday after the company's President Bai Zhongren died and investors expressed concerns about the cause of death.

The Beijing-based company said Bai died "in an accident" at home on Saturday, without giving specific causes.

In Shanghai, its shares yesterday fell 4.2 percent, the largest daily loss since October 15, to 2.51 yuan (41 US cents).

Its Hong Kong-listed shares dropped [Company Incorporation USA]4.1 percent to HK$3.75 (48 US cents) before touching as low as HK$3.63.

The operation of the company remains normal and its chairman, Li Changjin, will assume Bai's responsibilities until a new appointment is named, according to its filing to the Shanghai Stock Exchange on Sunday.

Market investors are concerned about the real reason behind Bai's death after media reports said he suffered from depression in recent years and jumped to his death from a building, citing unidentified sources.

The company's third-quarter report showed its net profit jumped 46.4 percent in the first nine months from the same period in 2012 to 6.26 billion yuan, while debts totaled nearly 85 percent of total assets.

Yu Teng, a spokesperson of China Railway, told China News Service yesterday that the company's business is [Company Registration in USA] in good shape and the debts are controllable.

Bai, 53, last appeared on TV on December 31 when he met with government officials in Nanning.

Bai's death is the second involving a high ranking railway personnel after investigations started into former railway minister Liu Zhijun in 2011. Liu was given a suspended death sentence in July for abuse of power and taking bribes.

In October 2011, Li Zhi, former head of the transport department of the Nanning Railway Bureau, committed suicide.