XINING, Aug. 27 (Xinhua) -- With sound development and greater innovation, private businesses have played a bigger part in China's pursuit of high-quality economic growth.

The total revenue of China's top 500 private companies reached 28.5 trillion yuan (4 trillion U.S. dollars) in 2018, up by 16.44 percent year on year, according to a report released by the All-China Federation of Industry and Commerce (ACFIC) last week.

Their total assets and net profits after tax also registered double-digit growth year on year, said the report.

Huawei peaked the 500 list with a revenue of 721.2 billion yuan in 2018. Top companies also include Suning, JD.com, and Legend Holdings.

To be listed, an enterprise needed to have revenues exceeding 18.59 billion yuan last year, higher than the 2017 threshold of 15.69 billion yuan.

A total of 20 private firms were also on the list of the world's top 500 companies, three more than last year.

Amid complex international and domestic conditions since last year, private enterprises have maintained a momentum of stable growth despite various risks and challenges, said Xu Lejiang, executive vice chairman of the ACFIC.

The private sector plays an important role in the economic system, contributing more than 50 percent of tax revenue, 60 percent of GDP, 70 percent of technological innovation, 80 percent of urban employment and 90 percent of new jobs and new firms.

In many sectors, private firms have become leading innovators, fueled by hefty R&D investment and a pioneering spirit in exploring new products and business models.

In the current industrial revolution powered by digital technologies, many Chinese firms are participants, promoters and in many sectors even bellwethers, said Xu.

Retail conglomerate Suning Holdings Group has long benefited from its early foray into online retailing. Building on such strength, the company launched a plan to develop smart retailing, with the goal of becoming a Chinese combination of Walmart and Amazon.

Since the plan started in late 2017, Suning has opened about 10,000 smart retail outlets across the country, a speed rarely seen in the industry.

"Our main strategy is to empower the retail industry with our experience and capabilities gained from 10 years of online practices," said Zhang Jindong, board chairman of Suning Holdings Group.

"Only when all companies can access new tech platforms and research results can the whole industrial chain be upgraded," added Zhang.

China's private firms have also been active in increasing their global presence and seizing overseas business opportunities.

In 2018, 241 private enterprises on the top 500 list invested in 2,345 overseas programs, with total revenue of about 815 billion dollars from overseas, according to the ACFIC report.

Private enterprises contributed more than half to China's foreign trade growth in 2018, a bright spot of China's foreign trade development, Li Kuiwen, spokesman of the General Administration of Customs, said earlier this year.

Partly due to insufficient credit support and limited market access, China's private enterprises have for a long time seen more difficulties in their development, compared with state-owned enterprises.

In recent years, China has taken various measures to promote private economy, including tax and fee cuts, expanding market access, streamlining approval and licensing procedures, as well as better financing.

A high-level symposium held in November, along with supportive policies unveiled afterward, has shored up private entrepreneurs' confidence.

China will unswervingly encourage, support and guide the development of the non-public sector and support private enterprises to develop toward a broader stage, according to a statement issued after the symposium.

"The Chinese government's policy support for private enterprises is unparalleled in the world," said Yue Kesheng, president of Guangdong-based Guosen Securities.

China has announced reducing the tax burden on and social insurance contributions of enterprises by nearly 2 trillion yuan this year, with a focus on the manufacturing sector and smaller businesses.

Measures to cut taxes and fees have saved 320 million yuan for agricultural conglomerate New Hope Group, said its chairman Liu Yonghao, who cited strong government support as an important reason for the continuing growth of China's private sector.

So far this year, machinery giant Sany Group has registered the best performance in its 33-year corporate history, according to its chairman Liang Wengen.

Such a stellar performance is partly due to the morale-boosting symposium, cuts of taxes and fees and the overall stable economy and machinery sector, said Liang.

"For our part, Sany has made great efforts in digital and intelligent transformation in a bid to achieve high-quality growth," said Liang.