A Chinese philanthropist known for his populist gestures has pledged to give domestically made cars to more than 40 people whose vehicles were damaged in widespread anti-Japan protests last month.

The protests erupted in cities across China last month over a dispute involving islets in the East China Sea, with some demonstrators targeting Japanese-brand cars.

Tycoon Chen Guangbiao, dressed in a lime-green suit and matching tie, on Wednesday showed off the dozens of Chinese-made Geely-brand replacement cars which he bought for a total of more than 5.0 million yuan ($794,000), state media said Thursday.

Some 43 people whose cars were damaged can swap their Japanese brands for the Geely vehicles to show their patriotism.

"I launched this event to remind people that patriotic behaviour should be conducted with rationality, wisdom and discipline," Chen said on his microblog late Wednesday.

Sales of Japanese-brand cars in China have plunged amid calls for boycotts against Japan's products, according to industry figures.

Chen, one of China's top 400 richest people with a fortune of $740 million, has handed out cash to victims of China's 2008 earthquake in Sichuan province and given away 3,000 pigs and sheep at a free music concert.

He has pledged to leave his entire fortune to charity after his death.

Chen's fortune is built on a recycling company, Huangpu Renewable Resources Utilization Group, based in the eastern city of Nanjing.