LONDON — Shakespeare may have had a little more help than previously suspected.

The New Oxford Shakespeare edition of the playwright’s works — which will be published by Oxford University Press online ahead of a worldwide print release — lists Christopher Marlowe as Shakespeare’s co-author on the three “Henry VI” plays, parts 1, 2 and 3.

It’s the first time that a major edition of Shakespeare’s works has listed Shakespeare’s colleague and rival as a co-author on these works, the volume’s general editor, Gary Taylor, said in a phone interview.

“No one has had the confidence to put the name actually on the title page,” Mr. Taylor said. “Which is perfectly reasonable because the only reason that we can do it now is because Shakespeare has entered the world of big data.”

The “Henry VI” plays have long been believed to be the work of more than one author. Names floated by scholars in addition to Marlowe’s include Robert Greene and George Peele.