China's Geely Holding, which already owns the Volvo Car Group, is buying an 8.2% stake in Swedish truck maker AB Volvo from activist investor Cevian Capital for around $3.3 billion.
Volvo Car Group was split from AB Volvo almost 20 years ago and Geely said it was not its current intention to try to reunite the two businesses.
"Given our experience with Volvo Car Group, we recognise and value the proud Scandinavian history and culture, leading market positions, breakthrough technologies and environmental capabilities of AB Volvo," Geely Chairman Li Shufu said.
Geely's expertise in the Chinese market and skills in developing electric and autonomous vehicles should help the truckmaker to expand, he added.
AB Volvo owns 45% of Dongfeng Commercial Vehicles, one of China's largest truck makers, and also has a significant construction equipment business in China.
The value of the investment amounted to around 27.2 billion Swedish crowns ($3.26 billion), a Reuters calculation showed.
However Geely and Cevian did not disclose the exact value of the transaction in their statement today.
The deal makes Geely the biggest individual shareholder in AB Volvo and second ranked in terms of voting rights behind Swedish investment firm Industrivarden.
Volvo shares have gained more than 50% this year as it and rivals in the truck industry such as Germany's Daimler and Volkswagen hit a sweet spot thanks to robust demand in major markets.
Cevian, which has held shares in Volvo since 2006, this year called for a break-up, suggesting the smaller Volvo Construction Equipment and engine and technology firm Volvo Penta should be separated from the main truck making business.
As well as Volvo cars which it acquired in 2010, Geely also owns the company that makes London's black cabs and sports carmaker Lotus.