The long anticipated Beijing-Shanghai high-speed railway will start a one-month trial operation on Wednesday, before its formal launch in late June, a railway official said.

The railway authority has also decided that the fastest train service between the two mega-cities will make an extra stop, according to an official with the transport bureau under the Ministry of Railways, who requested to remain anonymous.

"The train will stop at Nanjing (capital of Jiangsu province), because of the distance (1,318 km)," he said on Tuesday.

The travel time between Beijing and Shanghai will be about five hours, even though the ministry said earlier that the maximum operating speed was being reduced from 350 kilometers per hour to 300 km/h, he added.

Wang Yongping, the ministry's spokesman, said on Monday that the decision to lower the operating speed on high-speed railways was made to guarantee safety and reduce costs so the ticket prices can be reduced.

The ticket prices for the railway have yet to be announced, but the ministry has already submitted a proposal for ticket prices to the National Development and Reform Commission.

The decision to lower the operating speeds of high-speed trains is a big change introduced by the Ministry of Railways since Sheng Guangzu became the railways minister on Feb 25. He replaced Liu Zhijun, who stepped down when he became the subject of an investigation for an alleged "severe violation of discipline" on Feb 12.

However, trains on the Beijing-Tianjin high-speed line and a few other inter-city lines will continue to run at a top speed of 350 km/h.

On Tuesday, Sheng signed a deal with the Minister of Transport Li Shenglin in Beijing to strengthen the two ministries' cooperation on sea-rail transport.

The deal aims to streamline the container transport by using trains and ships, in order to cut the country's unusually high transport costs.

The China Federation of Logistics and Purchasing said the country's logistics accounted for 18 percent of the GDP in 2010, more than double that of developed countries.

China's ports handled 150 million twenty-feet equivalent units (TEU) of containers last year, of which only 2 percent were transported to the ports by train.

Song Dexing, director of the Ministry of Transport's water transport bureau, said that the percentage for key ports in Europe and the United States is around 15 percent.

Transporting containers by train is also more fuel-efficient, he added, and can reduce costs by 20 to 30 percent.