The China Enterprise Confederation (CEC) and the China Enterprise Directors Association jointly released the list of top 500 Chinese enterprises in 2011, providing a snapshot of China's corporate landscape.

Topping the ranking was Sinopec, China's largest oil refiner, which generated revenues of 1.97 trillion yuan ($307.7 billion) last year. It was followed by 1.72 trillion yuan ($268.9 billion) of PetroChina and 1.53 trillion yuan ($238.9 billion) of the State Grid.

The listed 500 companies listed raked in combined profits of 2.08 trillion yuan ($325 billion), up 38.7 percent from a year ago, while their total assets increased 18.4 percent to 108.1 trillion yuan ($16.9 billion). The threshold for entering the list was 14.2 billion yuan ($2.2 billion) of revenue, up 28.1 percent year on year.

Despite the torrid growth, worries abound about prospects for private firms. A total of 184 privately owned enterprises entered the list this year, but their combined profits were less than half of the top 10 companies, which are all state-owned enterprises (SOEs). Huawei, the telecom equipment manufacturer, ranked 39th, the highest position among private firms. But its revenues stood at 185.1 billion yuan ($28.9 billion), barely 10 percent of Sinopec.

The enormous divide is a serious concern for China as private firms create more than 80 percent of jobs in the country and account for more than half of the country's GDP.

The SOEs have received greater government support and enjoyed easier access to resources than their private counterparts, said Li Jianming, CEC Vice President.

"The most urgent task is to remove the financing bottleneck choking development of private businesses," said Liu Yonghao, President of New Hope Group, a private agricultural company based in southwestern Sichuan Province.