Container shipping giants CMA CGM and Maersk recently said that they will cooperate in efforts to reduce emissions in the sector, including by supporting the use of methanol and aiding research into potential fuels like ammonia.
The shipping industry is grappling with which fuels and vessel technology to adopt on a large scale to meet an objective of net zero emissions by around the middle of the century.
Danish group Maersk has focused on so-called green methanol and last week announced the creation a new company to produce fuel.
French-based CMA CGM has turned to gas-powered vessels while also ordering ships that can use methanol.
"While these two fuel streams appear now as the most mature among existing solutions, both companies expect the future fuel mix of shipping will include other streams that should be developed in the coming years," CMA CGM and Maersk said in a statement.
Their partnership would notably involve work to develop standards for operating green methanol vessels and accelerating the readiness of ports to refuel ships with methanol.
The firms would also explore research on other potential fuel solutions like ammonia, or new technology for vessels, they added.
Shipping firms say low-carbon fuels still lack the scale to sharply cut the footprint of an industry that contributes about 3% of global emissions.
CMA CGM led the adoption of gas-powered ships as an alternative to traditional fuel oil and is now trying to develop biogas supply to achieve greater emissions savings compared with conventional gas.