Zhejiang Geely Holding Group is calling for Chinese automotive brands to step up research and development and regain ground lost to international rivals as China's auto market continues to falter.

The vehicles sales in China has been falling since 2018. This year, a total of 16.1 million vehicles were delivered from January to August, a 11 percent fall on the same period in 2018, according to the China Association of Automobile Manufacturers.

The association expects total sales this year to fall by at least 5 percent from 2018.

Chinese brands' market share is shrinking, with combined sales accounting for 38.9 percent of the total from January to August, down from 42.3 percent from the same period last year, according to the association.

"The only way to solve this problem is for all Chinese brands to work together instead of complaining, because this is the result of fair competition," said Geely Chairman Li Shufu at an industry forum held on Friday in Sichuan province.

"This share is determined by the market and it's determined by the customers," he said.

He called on Chinese brands to sharpen their competitive edge through improving research and investment, adding that research and investment instead of expanding production should constitute the largest part of car companies' operational investment.

Geely's investment in research and investment totaled 21 billion yuan ($2.96 billion) in 2018, accounting for 6.4 percent of the total revenue of the group that year, which is roughly the same proportion as international automotive groups. Over the past decade, the group that owns Geely, Volvo and other brands has invested over 100 billion yuan in research and development.

So far the group has established five major research and development facilities, employing up to 20,000 engineers.

The group is also leveraging the advantages of its brands to create synergy. For example, the CMA platform is now shared by Volvo, Lynk&Co and Geely-branded vehicles.

The on-board connectivity system called GKUI is available on 22 models of different brands, with their combined sales totaling over 1 million. It is also featured in Proton models, a Malaysian brand of which Geely acquired a stake in 2017. Geely-branded vehicles increased their share in China from 6.3 percent to 6.5 percent in the first half of the year. Last year, the group's total sales hit 2.5 million vehicles.

In the future, Geely will maintain strong research and development investment. "Geely's long-term strategic goals will not be affected by short-term market fluctuations. We must maintain our strategic strength, grit our teeth, and not relax," Li said.