The lawsuit accuses the British pop phenomenon of copying parts of Marvin Gaye's soul classic "Let's Get It On" for the Grammy-winning hit "Thinking Out Loud".
A part owner of Marvin Gaye's "Let's Get It On" is suing Ed Sheeran for $100 million after getting blocked from a similar lawsuit brought by other copyright owners.
Both lawsuits say the British songwriter copied parts of the soul classic for his Grammy-winning hit "Thinking Out Loud."
A lawyer for Structured Asset Sales said the new lawsuit's Thursday filing was necessary because a judge refused to let the company join a 2016 lawsuit by the family of a co-writer of Gaye's song.
That lawsuit, which is still pending in Manhattan federal court, seeks unspecified damages.
A lawyer for Sheeran and other defendants said in a letter to the judge in the original lawsuit that he will seek to have both lawsuits tossed out. He said they were baseless.
World's best-selling artist of 2017
Earlier this year, Ed Sheeran was named the best-selling artist in the world in 2017 by the global recorded music industry group IFPI.
Sheeran's ÷ (Divide) was the best-selling album of last year and "Shape of You" was the best-selling single, London-based IFPI said in its announcement.
Sheeran is the fifth recipient of the Global Recording Artist of the Year Award after One Direction (2013), Taylor Swift (2014), Adele (2015) and Drake (2016).