Millwall FC have announced a new five-year, seven-figure, partnership agreement with Euroferries Express up to and including the 2018/19 season.
The deal with the company also includes luxury coaches laid on for matchday travel from locations in Kent and London, as well as the company logon on both the home and away shirts.
Millwall Chairman John Berylson said: "We are pleased to welcome Euroferries Express on board for the 2014/15 season and beyond."
"Throughout the whole process of finding a new main partner, the most important factor was to make the right decision, not only to safeguard all that is good about our club, but to ensure the chosen company possesses the qualities we seek to follow previous trusted partners."
"That has undoubtedly been achieved, and I look forward to working alongside Euroferries Express throughout the duration of our partnership."
Commercial Director Alan Williams added: "We're delighted to be entering into what is an exciting deal with a progressive and proactive company such as Euroferries Express."
"Announcing the agreement, though, is just the first step. Across the coming weeks, months and years the club will be working side-by-side with them to ensure Millwall supporters can benefit from our link-up in as many ways as possible."
Euroferries Express Director Adrian Gillan said: "At Euroferries Express we look forward to bringing additional access and opportunities to the club to help build on its current fan base and highly acclaimed work within the local community."
"By partnering with Millwall we are looking to help the club broaden its appeal to the wider community by supplementing transport links, arranging special promotions for supporters and, last but not least, to be its shirt sponsor for the next five years."
The Lions are preparing for the upcoming season, hoping they can improve on their last campaign in the Championship, where they found themselves involved in a relegation battle.