Japan's Toyota Motor is to invest JPY 200bn ($1.83bn) in 20 new LNG-fuelled car carriers.
The Nikkei daily reported that the move is a response to tighter fuel rules from 2020.
Owners NYK, K Line and Toyota's Toyofuji Shipping will contract three to six vessels each, initially.
Toyota uses 60 ships a month to export cars.
Around 20 7,000-vehicle units will be replaced, mainly on North American routes.