China Postal Express & Logistics Co. plans to raise 9.98 billion yuan ($1.6 billion) in an initial public offering, to buy trucks and airplanes and build distribution centers.

The unit of state-owned China Post Group will sell as many as 4 billion yuan-denominated shares on the Shanghai stock exchange, according to a prospectus published Saturrday on the China Securities Regulatory Commission website. China Postal is the nation’s biggest courier service, according to its website.

The regulator is tightening rules to improve share pricing and disclosure, with CSRC Chairman Guo Shuqing saying in March that IPO prices are “too high.” Stocks that started trading in China this year rose by an average 21 percent from their IPO prices in their first trades, and closed the most recent trading session an average of 7.1 percent below their offering prices, according to data compiled by Bloomberg.

China Postal’s distribution network covers 31 provinces and regions and more than 200 countries around the world, according to the prospectus. The company employs 889,000 people, the report said.