China Great Wall would buy 20 Long March 3A rockets from the rocket technology research institute of China Aerospace Science and Technology Corp (CASTC) and eight Dongfanghong communication satellites from another CASTC institute, Xinhua said.
CASTC is also the state parent of China Great Wall Industry.
China Great Wall planned to handle three commercial satellite launches in 2011, it added.
The agreement was signed on the sidelines of the on-going Zhuhai air show in southern China.
The Long March rockets are the workhorses of China's satellite programme. One launched China's lunar exploration probe last month, the Chang'e-2.
China started its space programme in the 1960s.
In 2003, it became the third country after the United States and the former Soviet Union to put a man into space. It sent two men into orbit in 2005 and carried out a space walk in 2008.
China is also in the middle of placing a total of 35 orbiters in space to end its dependence on U.S. satellites for navigation and positioning services.
But China's ambitions have raised concerns of a space arms race with the United States and other powers since China blew up one of its own weather satellites with a ground-based missile in January 2007