The France Under-21 international is set to arrive on Tyneside for a medical ahead of his move from France as Alan Pardew looks set to secure his first signing of the January transfer window after missing out on Loic Remy.
A statement on Nancy's club website read: "After 46 games and two-and-a-half years in the Nancy shirt, Massadio Haidara is leaving his former club for Newcastle United, currently sixteenth in the Premier League.
"The two clubs have reached an agreement and will finalize the transfer on Tuesday."
Haidara could be the first of two signings at St. James' Park. The club also reportedly has a deal in place for Montpellier captain Mapou Yanga-Mbiwa and hopes to conclude both before the end of the week.