German owners MPC Container Ships (MPCC) and Ahrenkiel Steamship are the latest names to sign up to a group aiming to enforce low-sulphur fuel rules in shipping.
The Trident Alliance has more than 50 shipping companies working together as IMO 2020 approaches.
As members, MPCC have committed to comply with the new regulations and support effective and transparent enforcement of these regulations.
MPCC CEO Constantin Baack said joining allowed it to align with "an important network of like-minded industry peers, and support industry-wide calls for effective and transparent enforcement around the world.”
Michael Silies, CEO of Ahrenkiel Steamship, added: “By joining The Trident Alliance, our aim at Ahrenkiel Steamships is to show our support for fair competition and consistent enforcement of the new sulphur fuel regulations, while demonstrating our commitment to innovative thinking at sea and ashore.”
The Trident Alliance was founded in 2014.
Other members include Maersk, Hapag-Lloyd, Hamburg Sud, Ardmore Shipping, Fjord Line and Scorpio, plus charterer Cargill.
